Microcontrols 7DEOHRI&RQWHQWV - ComfortSite€¦ · 1.1.3. ZSM Current Zone Sensor Module Descriptions ... 28.1. Test 1: Verifying UCP Communication With UEM ... Microcontrols The

Microcontrols The Voyage Continues

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7DEOH�RI�&RQWHQWV

1. Introduction to Microcontrols ............................................................................................................. 62. Unitary Control Processor ................................................................................................................... 7

2.1. Proportional Integral Control..........................................................................................................................................7

3. Zone Sensor Module ............................................................................................................................. 83.1. Installation Differences between Microcontrol & Electromechanical ............................................................................8

1.1.1. ZSM Wiring............................................................................................................................................................81.1.2. ZSM Obsolete Descriptions....................................................................................................................................91.1.3. ZSM Current Zone Sensor Module Descriptions..................................................................................................101.1.4. ZSM Control Wiring Tables .................................................................................................................................11

4. Equipment Protection / Operation Timings And Features............................................................. 125. Microcontrol Component Descriptions And Part Numbers........................................................... 14

5.1. Unitary Control Processor (UCP) .................................................................................................................................145.2. Unitary Economizer Module (UEM) ............................................................................................................................145.3. Unitary VAV Module (UVM) ......................................................................................................................................155.4. Defrost Module (DFM).................................................................................................................................................155.5. Conventional Thermostat Interface (CTI) (BAYCTHI001C).......................................................................................165.6. Trane Communications Interface (TCI-1).....................................................................................................................165.7. Trane Communications Interface (TCI-2).....................................................................................................................175.8. Trane Communications Interface (TCI-3) (BAYICSI001B) ........................................................................................175.9. BAYSENS006A (Obsolete) / ASYSTAT661A (Obsolete) ..........................................................................................185.10. BAYSENS007A (Obsolete) / ASYSTAT662A (Obsolete) ......................................................................................185.11. BAYSENS008A (Obsolete) / ASYSTAT663A (Obsolete) ......................................................................................195.12. BAYSENS009A (Obsolete) / ASYSTAT664A (Obsolete) ......................................................................................195.13. BAYSENS010A (Obsolete) .....................................................................................................................................205.14. BAYSENS011A (Obsolete) .....................................................................................................................................205.15. BAYSENS012A (Obsolete) / ASYSTAT665A (Obsolete) ......................................................................................215.16. BAYSENS013A (Obsolete) .....................................................................................................................................215.17. BAYSENS013B (Obsolete)......................................................................................................................................215.18. BAYSENS014A (Obsolete) .....................................................................................................................................225.19. BAYSENS014B (Obsolete)......................................................................................................................................235.20. BAYSENS017A (Obsolete) .....................................................................................................................................235.21. BAYSENS018A (Obsolete) .....................................................................................................................................245.22. BAYSENS019A/020A/ASYSTAT666A (Obsolete)................................................................................................245.23. BAYSENS022A (Obsolete) .....................................................................................................................................255.24. BAYSENS023A/ASYSTAT667A (Obsolete)..........................................................................................................255.25. Obsolete Programmable Zone Sensor Modules ........................................................................................................265.26. Obsolete Programmable Zone Sensor Modules ........................................................................................................27

6. Microcontrol Accessories and What They Offer ............................................................................. 286.1. BAYSENS006B/ASYSTAT661B................................................................................................................................286.2. BAYSENS007B / ASYSTAT662B..............................................................................................................................286.3. BAYSENS008B / ASYSTAT663B..............................................................................................................................296.4. BAYSENS009B / ASYSTAT664B..............................................................................................................................296.5. BAYSENS010B ...........................................................................................................................................................306.6. BAYSENS011B ...........................................................................................................................................................306.7. BAYSENS013C ...........................................................................................................................................................316.8. BAYSENS014C ...........................................................................................................................................................316.9. BAYSENS015A Humidity Sensor (OHS, RHS) ..........................................................................................................326.10. BAYSENS016A Thermistor Sensor (OAS, SAS, RAS, CTS) .................................................................................326.11. BAYSENS017B / ASYSTAT669A..........................................................................................................................336.12. BAYSENS019B / ASYSTAT666B..........................................................................................................................33

1.1.5. BAYSENS019B Options Menu............................................................................................................................346.13. BAYSENS020B .......................................................................................................................................................35

1.1.6. BAYSENS020B Options Menu............................................................................................................................356.14. BAYSENS021B .......................................................................................................................................................37


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6.15. Electronic Time Clock ..............................................................................................................................................376.16. High Temperature Sensor .........................................................................................................................................37

Section 2...................................................................................................................................................... 397. Start Up From The Unit "Test Mode Feature" ............................................................................... 39

7.1. Step Test Mode.............................................................................................................................................................397.2. Auto Test Mode ............................................................................................................................................................397.3. Resistance Test Mode ...................................................................................................................................................397.4. Test Mode Voyager 3-25 ..............................................................................................................................................407.5. VAV Test Mode Voyager 27.5-50................................................................................................................................417.6. CV Test Mode Voyager 27.5-50...................................................................................................................................417.7. UCP Default Control ....................................................................................................................................................42

1.1.7. Constant Volume 3-50 Ton...................................................................................................................................421.1.8. VAV 27.5-50 Ton.................................................................................................................................................42

7.8. Providing Temporary (default) Heating And Cooling ..................................................................................................437.9. Tracer / Tracker / ComforTrac / Comfort Manager ......................................................................................................44

8. LED Locations and Status Information ........................................................................................... 458.1. Unitary Control Processor LED....................................................................................................................................458.2. Unitary Economizer Module LED................................................................................................................................458.3. TCI-1 - LED .................................................................................................................................................................468.4. TCI-2 And 3 - LED.......................................................................................................................................................46

9. Cooling Start Up From The Zone Sensor Module (ZSM) Or Thermostat.................................... 479.1. Cooling Mode ...............................................................................................................................................................47

1.1.9. Cooling Staging 3-25 Tons ...................................................................................................................................471.1.10. Cooling Staging 27.5-50 Tons ..............................................................................................................................47

9.2. Economizer Operation 3-50 ton Constant Volume Units..............................................................................................499.3. Dry Bulb Change Over - Field Selectable.....................................................................................................................509.4. Single Enthalpy "Reference" Change Over - Field Selectable......................................................................................509.5. Differential Enthalpy "Comparative" Change Over......................................................................................................519.6. Economizer And Options 3-50 ton Constant Volume Units .........................................................................................529.7. Economizer Set Point- Constant Volume (3-50 tons) ..................................................................................................539.8. Economizer Set Point- Variable Air Volume (27.5-50 tons) .......................................................................................539.9. How The Economizer Functions Electrically ...............................................................................................................54

1.1.11. How The UCP Receives Information To Make Control Decisions ......................................................................541.1.12. How The UCP Causes Changes To Occur............................................................................................................54

10. Heating / Cooling Change Over ..................................................................................................... 5511. Gas Heat Start Up From The Zone Sensor Module (ZSM) Or Thermostat .............................. 56

11.1. Gas Heat Mode (Constant Volume 3-50 tons) ..........................................................................................................56

12. Electric Heat Start Up From The ZSM Or Thermostat .............................................................. 5812.1. Electric / Electric Heat Mode (Constant Volume 3-50 tons) ....................................................................................58

13. Heat Pump Start Up From The ZSM Or Thermostat ................................................................. 5913.1. Heat Pump Heating Mode (3-20 tons) WC Units .....................................................................................................59

14. Low Ambient Mechanical Cooling Operation.............................................................................. 6014.1. Evaporator Defrost Control (EDC) Function (3-25 Tons only) ................................................................................60

15. Defrost Operation............................................................................................................................ 6115.1. Demand Defrost........................................................................................................................................................6115.2. Demand Defrost Failures, Diagnostics, and Defaults ...............................................................................................6115.3. Time Temperature Defrost........................................................................................................................................6215.4. Time / Temperature Defrost Failures, Diagnostics, and Defaults .............................................................................6215.5. Soft Start ...................................................................................................................................................................6215.6. Smart Recovery.........................................................................................................................................................63

16. Operation with a Conventional Thermostat Interface (CTI)...................................................... 6317. Power Exhaust ................................................................................................................................. 64Section 3...................................................................................................................................................... 6518. Electrical Measurements................................................................................................................. 65

18.1. With Plugs Connected ..............................................................................................................................................6518.2. With Plugs Disconnected..........................................................................................................................................65


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18.3. At Disconnected Plug Ends ......................................................................................................................................66

19. Trouble Shooting From An Integrated Comfort System (ICS) Device ...................................... 6620. Recommended Steps For Trouble Shooting.................................................................................. 6721. Trouble Shooting Chart “Problem Descriptions And Causes”................................................... 6822. Component Failure And Response Chart ..................................................................................... 7123. Failure Status Diagnostics .............................................................................................................. 75

23.1. System LED..............................................................................................................................................................7523.2. Heat LED..................................................................................................................................................................7523.3. Cool LED..................................................................................................................................................................7623.4. Service LED..............................................................................................................................................................7623.5. Cool and Heat LED ..................................................................................................................................................7723.6. Service and Cool LED ..............................................................................................................................................7723.7. Service, Cool, and Heat LED....................................................................................................................................78

24. Failure Status Diagnostics .............................................................................................................. 7824.1. System ON = Measure DC volts between terminals LTB-6 & LTB-9 .....................................................................7824.2. HEAT = Measure DC volts between terminals LTB-6 & LTB-7. ............................................................................7924.3. COOL = Measure DC volts between terminals LTB-6 & LTB-8. ............................................................................7924.4. SERVICE = Measure DC volts between terminals LTB-6 & LTB-10. ....................................................................80

Section 4...................................................................................................................................................... 8125. Testing The Unitary Control Processor (UCP)............................................................................. 81

25.1. Test Mode Functions Properly but Erratic Normal Operation..................................................................................8125.2. Constant Volume 3-50 Ton.......................................................................................................................................8125.3. Variable Air Volume (VAV) 27.5-50 Ton................................................................................................................8125.4. Forcing Condenser Fan Cycling (12.5-25 Ton Only) ...............................................................................................8225.5. Forcing Condenser Fan Cycling (27.5-50 Ton) ........................................................................................................8225.6. Forcing Evaporator Defrost Control (EDC) Cycle (3-25 Ton) .................................................................................8225.7. Forcing Economizer Operation.................................................................................................................................82

26. Testing Zone Sensor Module (ZSM).............................................................................................. 8326.1. ZSM Terminal Identification ....................................................................................................................................8326.2. Test 1: UCP Zone Temperature Input Test..............................................................................................................8426.3. Test 2: UCP Cooling and Heating Set point Input Test ...........................................................................................8526.4. Test 3: UCP Mode Input Test ..................................................................................................................................8626.5. Test 4: LED Indicator Test ......................................................................................................................................86

27. Testing The Programmable Zone Sensor Modules (ZSMs) ........................................................ 8727.1. Programmable Troubleshooting Chart......................................................................................................................88

28. Testing Unitary Economizer Module (UEM)................................................................................ 8928.1. Test 1: Verifying UCP Communication With UEM .................................................................................................8928.2. Test 2: Verifying That The ECA Is Functional.........................................................................................................9028.3. Test 3: Testing The UEM Minimum Position Potentiometer ...................................................................................9028.4. Test 4: Testing Sensor Inputs And Exhaust Fan Output ...........................................................................................9128.5. Test 5: Testing the Sensors .......................................................................................................................................95

29. Testing The Defrost Module (10-20 Ton Heat Pumps only)...................................................... 10029.1. Test 1: Simulates an open Defrost Termination Switch (DT) .................................................................................10129.2. Test 2: Simulates a closed Defrost Termination Switch (DT) ................................................................................10129.3. Test 3: Testing The SOV Relay Circuit ..................................................................................................................102

30. Testing The Coil Temperature Sensor (CTS) ............................................................................. 10431. Testing The CTI (3-50 Ton CV only)........................................................................................... 107

31.1. Test 1: Testing The Mode Output...........................................................................................................................10731.2. Test 2: Testing The Cooling Set Point Output ........................................................................................................10831.3. Test 3: Testing The Heating Set Point Output ........................................................................................................10931.4. Test 4: Testing The Zone Temperature Output.......................................................................................................110

32. Testing the Exhaust Fan Set Point Panel (27.5-50 Ton)............................................................. 11133. Unit Variable Air Volume Module (UVM) Test Procedures (27.5-50 Ton)............................. 112

33.1. Test 1: Testing Inlet Guide Vane/Variable Frequency Drive (IGV/VFD) Output ..................................................11233.2. Test 2: Testing the Static Pressure Transducer Input.............................................................................................112


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33.3. Test 3: Testing the Temperature Sensor Input ........................................................................................................11233.4. Test 4: Testing the VAV Set Point Input ...............................................................................................................11333.5. Test 5: Testing the Inlet Guide Vane Actuator (IGVA).........................................................................................11333.6. Test 6: Testing the VFD.........................................................................................................................................11333.7. Test 7: Testing the VAV Set Point Panel...............................................................................................................114

34. Testing The UCP / TCI Interface................................................................................................. 11834.1. Test 1: Testing The UCP Output To The TCI ........................................................................................................118

Section 5.................................................................................................................................................... 12135. Erratic Unit Operation (3-25 ton) ................................................................................................ 121

35.1. Economizer wiring harness has conductor(s) shorted to ground:............................................................................12135.2. Equipment wiring harness damaged in factory installation:....................................................................................12135.3. A terminal backed out of the 15 pin polarized plug:...............................................................................................12135.4. J4 or J5 on the UCP not wired or plugged in properly (3-50 ton): .........................................................................12135.5. The polarized plugs are not configured properly on Heat Pump (3-20 ton): ..........................................................122

36. The Equipment Fails To Energize Or De-Energize A Component........................................... 12336.1. A UCP on board relay may have failed: .................................................................................................................12336.2. Brass jumpers for compressor disable input are loose, corroded or missing: .........................................................123

37. Will Not Work With A CTI (Constant Volume only) ................................................................ 12438. No Communication Between ICS Device & Voyager................................................................. 124

38.1. TCI-1 is being utilized: ...........................................................................................................................................12438.2. TCI-3 is being utilized, and Com Link board Non-isolated Comm: .......................................................................12438.3. DIP switches on the TCI are set incorrectly:...........................................................................................................12538.4. The comm link is connected to Comfort Manager incorrectly:...............................................................................12538.5. No Communication Between Comfort Manager & Voyager ..................................................................................12538.6. TCI-2 is being utilized: ...........................................................................................................................................12538.7. TCI-3 is being utilized, and Com Link board Non-isolated comm: ........................................................................12538.8. DIP switches on the TCI are set incorrectly:...........................................................................................................12638.9. An ICS component failure may have occurred: ......................................................................................................126

39. Sensors Fail And Return To Normal On An ICS Installation .................................................. 12739.1. Moisture on UEM has compromised integrity of conformal coating:.....................................................................127

40. Temperature Swings, Bounces Between Heating And Cooling ................................................ 12840.1. ZSM installation/location can accentuate zone temperature swings: ......................................................................128

41. Evaporator Coil Icing (3-25 ton) .................................................................................................. 12941.1. Low ambient mechanical cooling with large quantities of outdoor air: ..................................................................12941.2. Excessive amounts of bypass from discharge to return air intake:..........................................................................12941.3. Operating mechanical cooling under low air flow, or low refrigerant charge:........................................................12941.4. Operating equipment in a process application, with a sub-cooled zone:.................................................................12941.5. Failure or removal of Outdoor Air Sensor (OAS): .................................................................................................129

42. Solutions To Evaporator Coil Icing (3-25 ton) ........................................................................... 13042.1. Installing a direct sensing evaporator defrost control (EDC):.................................................................................13042.2. Modifying configuration of condenser fan cycling temps (12.5-25 Ton): ..............................................................13142.3. Installing a head pressure control device to modulate condenser fan speed: ..........................................................13142.4. Installing hot gas bypass, liquid injection type: ......................................................................................................13242.5. Installing hot gas bypass, bypass to evaporator inlet: .............................................................................................132

43. Conditions Which Can Cause Incomplete Heat Pump Defrost ................................................ 13343.1. OAS out of calibration/mis-located (Demand Defrost 3-7.5 Ton):.........................................................................13343.2. CTS out of calibration/mis-located (Demand Defrost 3-7.5 Ton): .........................................................................13343.3. DT out of calibration/mis-located (Time/Temp. Defrost 10-20 Ton): ....................................................................133

44. UCP F1 Fuse Or TNS1 Transformer Over Current Device Blows........................................... 13445. Multiple UCP U5 Chip Failures................................................................................................... 135

45.1. Factory or Field mis-wire of AC voltage to U5 chip: .............................................................................................13545.2. Replacing defrost or condenser fan DC relays, with AC coils: ...............................................................................135

46. Multiple UCP U6 Chip Failures................................................................................................... 13646.1. Failure to install edge protector on a raw metal edge (Voyager 3-25): ...................................................................13646.2. Wiring harness damaged in factory installation (Voyager 3-25): ...........................................................................13646.3. Replacing power exhaust relay, with AC coil relay: ...............................................................................................136


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Section 6.................................................................................................................................................... 13747. Pin Descriptions & Voltages ......................................................................................................... 137

47.1. Voltages And Descriptions Available At The LTB, Prior To 06/93.......................................................................13747.2. Voltages And Descriptions Available At The LTB, After 06/93 (3-50 ton) ...........................................................13747.3. Voyager 27.5-50 Ton LTB-2 Pin Descriptions & Voltages....................................................................................13847.4. Voyager 27.5-50 Ton LTB-3 Pin Descriptions & Voltages....................................................................................13847.5. Voyager 27.5-50 Ton LTB-4 Pin Descriptions & Voltages....................................................................................13847.6. UCP Pin Descriptions & Voltages 3-25 Ton ..........................................................................................................13947.7. UCP Pin Descriptions & Voltages 27.5-50 Ton .....................................................................................................14147.8. UEM Pin Descriptions & Voltages 3-50 Ton .........................................................................................................14347.9. UVM Pin Descriptions & Voltages 27.5-50 Ton....................................................................................................14447.10. VAV Set Point Panel 27.5-50 Ton..........................................................................................................................14547.11. DFM Pin Descriptions & Voltages 3-20 Ton .........................................................................................................14647.12. CTI Pin Descriptions & Voltages 3-50 Ton............................................................................................................14647.13. TCI-1 Pin Descriptions & Voltages 3-50 Ton ........................................................................................................14747.14. TCI-2 Pin Descriptions & Voltages 3-50 Ton ........................................................................................................14747.15. TCI-3 Pin Descriptions & Voltages 3-50 Ton ........................................................................................................148

48. Low Voltage Identification Through Wire Color Coding (3-25 only)...................................... 14949. General Specifications Of Control Components ........................................................................ 15050. Microcontrol Printed Circuit Board Switch Settings................................................................. 151

50.1. Unitary Control Processor (UCP) Switch Setting Table .........................................................................................15150.2. Unitary Economizer Module (UEM) Switch Setting Table ....................................................................................15150.3. Defrost Module (DFM) Switch Setting Table (10-20 ton)......................................................................................15150.4. Unitary Variable Air Volume Module (UVM) switch settings (27.5-50 ton) .........................................................151

51. UCP Configuration Input (3-25 ton) ........................................................................................... 15252. UCP Configuration Input (27.5-50 ton) ...................................................................................... 15253. UCP “Snubber Circuits” .............................................................................................................. 15354. UCP Outputs To 29 - 32 Volt DC LOADS.................................................................................. 15455. Software Change History.............................................................................................................. 155

55.1. 3-25 ton UCP Identification And Software Change History...................................................................................15555.2. 27.5-50 ton UCP Identification And Software Change History..............................................................................15755.3. 3-50 ton CTI Identification And Software Change History ....................................................................................158


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1. Introduction to Microcontrols

The Voyager Micro was developed with two specific thoughts in mind: comfort and reliability. It providesProportional/Integral control for superior temperature control and eliminates the need to add time delay relays or anti-shortcycle times in the field. The Micro also reduces the number of parts in the control system, which means fewer parts to fail andtroubleshoot. In the unlikely event that a problem does occur, the Micro’s on-board diagnostics are there to assist and get youback on-line fast. Trane is a pioneer in the application of microprocessor controls in the HVAC industry and has extensiveexperience in the design of hardware and software.


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2. Unitary Control Processor

The Unitary Control Box (UCP) located in the unit control box includes the following functions:

• Controls decision making processes in the unit control box• Functions as a Proportional Integral Control.• Enables temperature control.• Contain equipment protection and operational enhancement features.

Unitary Control Processor as a Decision Making Process

2.1. Proportional Integral Control

Proportional Integral Control (PI), located in the UCP enables space temperature control by the following:

• Sets the corrective action proportional to the error of deviation from the set point.• Sets the rate of corrective action proportional to the error, resulting in the elimination of steady state error.

Proportional Integral Control as a Corrective Action


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3. Zone Sensor ModuleThe Zone Sensor Modules (ZSM) replaces a thermostat by providing the operator interface and zone temperature sensor inputfor the UCP. A Zone Sensor Module (ZSM) is required for each constant volume system, unless a Conventional ThermostatInterface (CTI), VariTrac II with CCP or VariTrac Comfort Manager is being used. Variable Air Volume (VAV) systems canuse similar controllers, or they can be operated from the VAV panel in the rooftop unit plus shorting the low voltage terminalboard terminals 2 and 4 (LTB1-2 and LTB1-4) for a mode input.

All stand alone ZSMs are available with the following items:• Remote sensing capabilities• Space temperature averaging capabilities (exceptions include obsolete sensors)• Single or Dual set point• Programmable models

3.1. Installation Differences between Microcontrol & Electromechanical

1.1.1. ZSM WiringThere are differences between the microelectronic control units and electromechanical units. The biggest and most dramaticdifference is that the industry standard terminal designations no longer exist, in other words, “R-G-Y-W-B” are no longer used.This is a very big change, but in reality it is a simplification, terminal designations are now 1-2-3-4-5 etc.

The terminal designations on the Zone Sensor Modules (ZSMs) are identical to the terminal designations on the customerconnection, or Low Voltage Terminal Board (LTB). No more wondering what thermostat terminal goes to what unit terminal.Customer control wiring connections are as simple as: 1 to 1, 2 to 2, 3 to 3, 4 to 4, 5 to 5, and so on.

Note: VAV units use the VAV set point panel for supply air and MWU inputs instead of 3 and 5.


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1.1.2. ZSM Obsolete Descriptions

Obsolete Zone Sensor Module DescriptionAccessory Zone Sensor Required # TerminalModel # Module Description Conductors Description

Heat/CoolBAYSENS006A Single Set Point 4 1,2,3,4ASYSTAT661A Manual Change Over

BAYSENS008A Dual Set Point 5 1,2,3,4,5ASYSTAT663A Manual / Auto

Change Over

BAYSENS010A Dual Set Point with 10 1,2,3,4,5, LEDs Manual / Auto 6,7,8,9,10 Change Over

BAYSENS019A/020A Programmable with 3-7ASYSTAT666A Night Setback and 12,14

LCD Indicators 7-10 OptionalHeat Pump

BAYSENS007A Single Set Point 6 1,2,3,4,ASYSTAT662A Manual Change Over 6,7

BAYSENS009A Dual Set Point 7 1,2,3,4,5,ASYSTAT664A Manual / Auto 6,7

Change Over

BAYSENS011A Dual Set Point with 10 1,2,3,4,5, LEDs Manual / Auto 6,7,8,9,10 Change Over

BAYSENSO23AProgrammable with 3-7 7,8,9,10,11,ASYSTAT667A Night Setback and 12,14

LCD Indicators 7-10 OptionalHeat / Cool Or Heat Pump

BAYSENS012A Programmable With 2 11,12ASYSTAT665A Night Setback

BAYSENS018A Programmable With 6 7,8,9,10, Night Setback And 11,12 LCDs

BAYSENS022A Digital with LCD 3 11,12,14Temperature Display

Tracer / Tracker / ComforTrac ICSBAYSENS013A Override Sensor 2 1,2BAYSENS013B

BAYSENS014A Override Sensor 3 1,2,3BAYSENS014B with Set Point


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1.1.3. ZSM Current Zone Sensor Module Descriptions

Current Zone Sensor DescriptionsAccessory Zone Sensor Required # TerminalModel # Module Description Conductors Description

Heat/CoolBAYSENS006B Single Set Point 4 1,2,3,4ASYSTAT661B Manual Change Over

BAYSENS008B Dual Set Point 5 1,2,3,4,5ASYSTAT663B Manual / Auto

Change Over

BAYSENS010B Dual Set Point with 10 1,2,3,4,5, LEDs Manual / Auto 6,7,8,9,10 Change Over

BAYSENS019B/020B Programmable with 3-7 7,8,9,10,ASYSTAT66B Night Setback and 12,14,

LCD Indicators 7-10 optional

BAYSENS021A VAV Remote Panel 4-9 1,2,3,4,6,7,W/OUT Night Setback 8,9,10

6-10 optionalHeat Pump

BAYSENS007B Single Set Point 6 1,2,3,4,ASYSTAT662B Manual Change Over 6,7

BAYSENS009B Dual Set Point 7 1,2,3,4,5,ASYSTAT664B Manual / Auto 6,7

Change Over

BAYSENS011B Dual Set Point with 10 1,2,3,4,5, LEDs Manual / Auto 6,7,8,9,10 Change Over

Tracer / Tracker / ComforTrac ICSBAYSENS013C Override Sensor with 2 1,2

Override Cancel

BAYSENS014C Override Sensor with 3 1,2,3 Set Point and Override Cancel


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1.1.4. ZSM Control Wiring Tables

Control Wiring Tables

Standard Zone Sensor Module Conventional ThermostatWire Size Maximum Wire Length Wire Size Maximum Wire Length22-gauge 150 feet 22-gauge 30 feet20-gauge 250 feet 20-gauge 50 feet18-gauge 375 feet 18-gauge 75 feet16-gauge 600 feet 16-gauge 125 feet14-gauge 975 feet 14-gauge 200 feet

Zone Sensor Module (ZSM) to Low VoltageTerminal Board (LTB), and Remote Sensor toZone Sensor Module (ZSM).

Conventional Thermostat Interface (CTI) Installation(CV Only).Standard Thermostat to Low Voltage Terminal Board (LTB).

Wire Type = Standard Thermostat Wire, solid conductor Wire Type = Standard Thermostat Wire, Solid Conductor.Note: Total resistance must not exceed 5 Ohms, or ZSMcalibration / accuracy may be affected.

Note: Total resistance must not exceed 1 Ohm, or CTI andlow voltage transformer will be over powered.

Remote Sensor to Programmable ZSM. ICS Device (Tracer, Tracker, ComforTrac, Comfort Manager) to Trane Communication Interface (TCI).

Type = Shielded Twisted Pair of Conductors. Type = Shielded Twisted Pair of Conductors.

Specification = 18-gauge / Belden 8760 or equivalent. Specification = 18-gauge / Belden 8760 or equivalent.

Length = 1,000 feet, or less. Length = 5,000 feet, or less.


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4. Equipment Protection / Operation Timings And Features

Increased Reliability –• Fewer components (moving electromechanical parts), less likelihood of equipment down time or failure. Standard

Direct Digital Control (DDC) –• Proportional Integral (PI) control. Proportional - sets corrective action proportional to deviation from set point. Integral -

fine-tunes the rate of corrective action proportional to the error (results in superior space temperature control). Standard

Built In “TEST” Mode -• Aids in quick verification of system and control operation, exercises both hardware and software (no special tools

required). Standard

On Board Diagnostics –• Assist with equipment troubleshooting, if a problem occurrence should take place. Standard

Low Ambient Start Timer (LAST) Function –• Bypasses low pressure control when a compressor starts, eliminating nuisance compressor lockouts. Standard

Anti Short Cycle Timer (ASCT) Function –• Provides a three (3) minute minimum “ON” time and a three (3) minute minimum “OFF” time for compressors, enhances

compressor reliability by ensuring proper oil return. Standard

Time Delay Relay (TDR) Function –• Provides an incremental staging delay between compressors, minimizes equipment current inrush and consumption by

keeping compressors from starting simultaneously. Standard

Built In Fan Delay Relay (FDR) Function –• Provides custom indoor fan timing sequences for the different types of equipment, enhancing efficiency and reliability.

Standard

Built In Evaporator Defrost Control Function –• Provides low ambient cooling down to 0° F. Standard• Built in Frostat for Voyager 27.5-50 ton units - Provides low ambient cooling down to 0 F. Standard

Integral Electric Heat Staging –• Stages electric heaters “OFF” and “ON”, eliminating the use of outdated sequencers. Standard

Intelligent Fallback –• A built in Default Control provides adaptive operation, which allows the equipment to continue to operate, providing

comfort in the event of certain component failures. Also, allows emergency operation without a Zone Sensor Module(ZSM). Standard

Emergency Stop Terminals on Low Voltage Terminal Board (LTB-16 & LTB-17) –• Provides a convenient point to disable the equipment completely, and immediately. Standard

Lower Installation Cost –• Using a standard Zone Sensor Module (ZSM), control voltage wiring may be run up to five (5) times further than any

electromechanical system, with no increase in wire gauge. Example: Electromechanical System - 30 feet maximum using22-gauge wire. Microcontrol System - 150 feet using 22 gauge wire. Standard


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Alternating Lead/Lag –• (Dual Compressor or Dual Circuit Models Only) During periods of part load operation, each compressor cycles alternately

as circuit number one, equalizing compressor wear and run time. Enabled by cutting the wire at UCP junction number J1-7.Standard

Demand Defrost on 3-7.5 Ton Heat Pumps –• Defrosts only if needed, not based on time like most other systems, optimizing and lowering operating costs. Standard

Heat Pump on 3-20 Ton Soft Start –• Provides a smooth transition into heating after defrost, minimizing noise and compressor stress associated with switch over.

Standard

Heat Pump on 3-20 Ton Smart Recovery and Smart Staging –• Inhibits auxiliary heat operation if the space is recovering adequately (0.1° F./minute) with the heat pump alone, providing

considerable savings in operating costs. Standard

Remote Sensing –• All standard Zone Sensor Modules (ZSMs) have remote sensing capabilities, with the exception of some obsolete sensors.

Space Temperature Averaging –• All standard ZSMs have space temperature averaging capabilities. Requires a minimum of four (4) remote sensors.

Supply Air Tempering –• A built in feature may also be enabled using a digital or programmable Zone Sensor Module. When in the HEAT mode

(and not actively heating), if supply air temperature drops 10° F. below the heating set point, heat is turned on until supplyair temperature rises to a point 10° F. above the heating set point. Provides temperate air during the “OFF” cycle, andeliminates cold air dumping from supply ducts. Extremely effective when introducing any quantity of fresh air. Standardwhen using an ICS device, digital, or programmable Zone Sensor Module

Built In Night Set Back And Unoccupied Functions –• When using a standard dual set point/auto change over Zone Sensor Module (ZSM), this function is enabled by applying a

short across terminals LTB-11 and LTB-12. Sets cooling set point up a minimum of 7° F., sets heating set point back aminimum of 7° F., forces outside air damper (if present) minimum position to zero, and forces fan operation to automatic.Accessory (requires time clock accessory or field supplied/installed switch or contacts)

• When using a standard single set point/manual change over ZSM still short between terminals LTB-11 and LTB-12 forunoccupied function, but you will only get the fan automatic operation not the temperature set back of 7° F. Accessory(requires time clock accessory or field supplied/installed switch or contacts)

• For VAV- mechanical cooling is disabled, outside air damper will close, and the fan goes to automatic mode. IGV’s andVAV boxes are forced open during transition from OCC/UNOCC.

Selectable Economizer Dry Bulb Change Over –• Allows the capability of selecting the following dry bulb change over points: 55, 60 or 65° F. Standard with economizer

accessory

Economizer Preferred Cooling –• Provides fully integrated operation if required. Will not turn on a compressor with the economizer, if the space is

recovering adequately with the economizer alone (0.2° F./minute). Allows the equipment to be utilized in more variedapplications. Standard with economizer accessory

Morning Warm-Up Control – (VAV units)• With a programmable sensor ICS device or standard VAV set point panel .

Daytime Warm-Up Control – (VAV units)• When using morning warm-up the daytime control is also available or can be eliminated. Standard


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5. Microcontrol Component Descriptions And Part Numbers

5.1. Unitary Control Processor (UCP)Main board in the unit control box, standard in all microcontrol units, the computer and program reside in this board. This is theheart of the control system.

Component Description Part Number

Unitary Control Processor (UCP) 3-25 tons MOD-0432Unitary Control Processor (UCP) 27.5-50 tons MOD-0405

5.2. Unitary Economizer Module (UEM)Board located in accessories, standard in all microcontrol economizers, motorized outside air dampers, and BAYDIAG001A,allows UCP to directly control the economizer actuator (ECA). This is the hardware interface between the UCP and theeconomizer actuator (ECA) motor.


Unitary Economizer Module (UEM) MOD-0145


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5.3. Unitary VAV Module (UVM)Optional board on VAV units that provides a 2 to 10 VDC output to control IGV’s and VFD’s.


Unitary VAV Module (UVM) MOD-0146

5.4. Defrost Module (DFM)Small board located in the bottom of heat pump control boxes, comes in 10-20 ton microcontrol heat pumps only, providestemperature input to the UCP for time / temperature defrost.


Defrost Module (DFM) BRD-0742


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5.5. Conventional Thermostat Interface (CTI) (BAYCTHI001C)Accessory (BAYCTHI001C) field installed board, mounted in unit control box to the right of the UCP board. Allows system tobe operated by a thermostat or through dry contact closure type controls. The only difference between VI/VII/VIII is the cablelength from the UCP to the CTI.


Conventional Thermostat Interface (CTI) BRD-0968

5.6. Trane Communications Interface (TCI-1)Accessory field installed board, mounted in unit control box to the right of the UCP board. Allows system to communicate with,and be controlled by, Tracer / Tracker / ComforTrac Integrated Comfort System (ICS) Building Management Devices.


Trane Communications Interface (TCI-1) MOD-0016


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5.7. Trane Communications Interface (TCI-2)Accessory field installed board, mounted in unit control box to the right of the UCP board. Allows system to communicate with,and be controlled by, Tracer / Tracker / ComforTrac Integrated Comfort System (ICS) Building Management Devices.


Trane Communications Interface (TCI-2) MOD-0043

5.8. Trane Communications Interface (TCI-3) (BAYICSI001B)

Accessory field or factory installed board, mounted in unit control box to the right of the UCP board. Allows system tocommunicate with, and be controlled by Tracer / Tracker / ComforTrac / VariTrac Comfort Manager / VariTrac II with CCP /and the “STAT” 4-16 series of products (Tracker / ComforTrac / VariTrac not used with VIII VAV).


Trane Communications Interface (TCI-3) BRD-0917


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5.9. BAYSENS006A (Obsolete) / ASYSTAT661A (Obsolete)Accessory Heat / Cool Zone Sensor Module (ZSM), single set point, manual change over. Four conductors required.Manufactured by Sunne prior to 12/93.


BAYSENS006A (Obsolete) [Sunne part# 38947] SEN-0279ASYSTAT661A (Obsolete) [Sunne part# 39112] SEN-0289

5.10. BAYSENS007A (Obsolete) / ASYSTAT662A (Obsolete)Accessory Heat Pump Zone Sensor Module (ZSM), single set point, manual change over. Six conductors required.Manufactured by Sunne prior to 12/93.




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5.11. BAYSENS008A (Obsolete) / ASYSTAT663A (Obsolete)Accessory Heat / Cool Zone Sensor Module (ZSM), dual set point, manual / auto-change over. Five conductors required.Manufactured by Sunne prior to 12/93.



5.12. BAYSENS009A (Obsolete) / ASYSTAT664A (Obsolete)Accessory Heat Pump Zone Sensor Module (ZSM), dual set point, manual / auto-change over. Seven conductors required.Manufactured by Sunne prior to 12/93.


BAYSENS009A (Obsolete) [Sunne part# 38944 SEN-0287ASYSTAT664A (Obsolete) [Sunne part# 39115] SEN-0293


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5.13. BAYSENS010A (Obsolete)Accessory Heat / Cool Zone Sensor Module (ZSM), dual set point with LEDs, manual / auto-change over. Ten conductorsrequired. Manufactured by Sunne prior to 12/93.


BAYSENS010A (Obsolete) [Sunne part# 38945] SEN-0281

5.14. BAYSENS011A (Obsolete)Accessory Heat Pump Zone Sensor Module (ZSM), dual set point with LEDs, manual / auto-change over. Ten conductorsrequired. Manufactured by Sunne prior to 12/93.




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5.15. BAYSENS012A (Obsolete) / ASYSTAT665A (Obsolete)Accessory Heat / Cool and Heat Pump, programmable night set back Zone Sensor Module (ZSM). Two conductorsrequired. Manufactured by Enerstat/Valera prior to 02/94.


BAYSENS012A (Obsolete) [Valera part# CT-7] SEN-0282ASYSTAT665A (Obsolete) [Valera part# CT-7 SEN-0291

5.16. BAYSENS013A (Obsolete)Accessory ICS (Tracer/Tracker/ComforTrac) Zone Sensor Module (ZSM), with override button. Two conductors required.Manufactured by Sunne prior to 12/93.



5.17. BAYSENS013B (Obsolete)Accessory ICS (Tracer/Tracker/ComforTrac) Zone Sensor Module (ZSM), with override button. Two conductors required.Manufactured by Sunne, prior to 08/95.


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BAYSENS013B [Sunne part# 62829] SEN-0438

5.18. BAYSENS014A (Obsolete)Accessory ICS (Tracer/Tracker/ComforTrac) Zone Sensor Module (ZSM), with override button and set point. Threeconductors required. Manufactured by Sunne prior to 12/93.




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5.19. BAYSENS014B (Obsolete)Accessory ICS (Tracer/Tracker/ComforTrac) Zone Sensor Module (ZSM), with override button and set point. Three conductorsrequired. Manufactured by Sunne, prior to 08/95.



5.20. BAYSENS017A (Obsolete)Accessory Zone Sensor Remote, used with BAYSENS006A, 007A, 008A, 009A, 010A or 011A. Two conductors required.Manufactured by Sunne prior to 12/93.




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5.21. BAYSENS018A (Obsolete)Accessory Heat / Cool and Heat Pump, programmable night set back Zone Sensor Module (ZSM), with LCD status / diagnosticindicators. Six conductors required. Manufactured by Enerstat/Valera prior to 02/94.


BAYSENS018A (Obsolete) [Valera part# CTS-7] SEN-0305

5.22. BAYSENS019A/020A/ASYSTAT666A (Obsolete)Accessory Heat/Cool, programmable night set back Zone Sensor Module (ZSM), with LCD status / diagnostic indicators.Seven conductors, terminals 11, 12 & 14 required, 7 through 10 optional. Manufactured by Heatcraft, introduced 03/94.


BAYSENS019A [Heatcraft part# 63J74] SEN-0415ASYSTAT666A [Heatcraft part# 67J57] SEN-0421


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5.23. BAYSENS022A (Obsolete)Accessory Heat / Cool and Heat Pump, (non-programmable) digital Zone Sensor Module (ZSM), with LCD display. Threeconductors required. Manufactured by Enerstat/Valera, introduced 06/93.


BAYSENS022A [Valera part# DSPCT7] SEN-0427

5.24. BAYSENS023A/ASYSTAT667A (Obsolete)Accessory Heat Pump, programmable night set back Zone Sensor Module (ZSM), with LCD status / diagnostic indicators.Seven conductors, terminals 11, 12 & 14 required, 7 through 10 optional. Manufactured by Heatcraft, introduced 03/94.


BAYSENS023A [Heatcraft part# 63J76] SEN-0416ASYSTAT667A [Heatcraft part# 67J56] SEN-0422


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5.25. Obsolete Programmable Zone Sensor ModulesThe programmable zone sensor module ( 56) is a night set back device with 7 day programming capabilities, and one occupied /unoccupied period per day. Installation is simple, the communication link provides operating power, and only two wires arerequired for BAYSENS012A or ASYSTAT665A installation. When remote panel indication is required, the BAYSENS018Ais utilized, six wires are required to complete its installation. A microprocessor in the zone sensor communicates with the UCPonce every 0.5 seconds, allowing rapid response to the comfort requirements of the zone.

Dip switch #1 controls the selection of 12 hour or 24-hour clock display. When switch #1 is “OFF” 12-hour clock is displayed,when “ON” 24 hour clock is displayed.

Dip switch #2 controls the selection of Fahrenheit or Centigrade temperature display. When switch #2 is “OFF”, temperatureis displayed in degrees Fahrenheit, when “ON” Centigrade is displayed.

Dip switch #3 enables the Computed Recovery feature, when enabled by turning zone sensor dip switch #3 “ON”, this allowsthe zone to be at the occupied temperature at the selected occupied time. As opposed to being in the process of recovering fromnight set back.

Dip switch #4 enables Unoccupied Functions, activated by turning zone sensor dip switch #4 “ON”, this forces the economizerminimum position to zero during the unoccupied mode.

Dip switch #5 selects Warm Up, or (“Unoccupied functions terminate at 2° F. from occupied temperature set point”) enabledby turning dip switch #5 “ON”. When changing from unoccupied to occupied mode, this keeps the outside air damper closeduntil the zone temperature is within 2° F. of the occupied set point.

Dip switch #6 controls the Smart Fan option, when switch #6 is turned “ON” the fan mode is forced to the AUTO mode whenthe equipment is in the unoccupied heating or cooling mode.

Dip switch #7 cons the sensor for Heat Pump or Heat/Cool operation. When switch #7 is turned “ON”, the sensor is configuredfor Heat/Cool operation, when turned “OFF” Emergency Heat operation is enabled.

Dip switch #8 enables and disables key pad lock out. When switch #8 is turned “OFF” the key pad operates normally, whenturned “ON” the programming functions are disabled. Reference publication THER-IN-43 for programming and / or additionalinformation.


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5.26. Obsolete Programmable Zone Sensor ModulesThe programmable zone sensor module ( 57), is a night set back device with many features. It has 7 day programmingcapabilities, with two occupied, and two unoccupied periods per day. Installation is simple, only three wires are required forbasic installation. When remote panel indication is needed, seven wires are used to complete installation. Its microprocessorcommunicates once every 0.5 seconds with the UCP, for rapid response to zone changes.

Zone Temperature Calibration: Set SYSTEM switch to “OFF”, press ENTER & CLEAR simultaneously until the FIELDCAL icon appears, press “+” & “-” until displayed temperature agrees with calibration instrument. Once calibration is complete,move the SYSTEM switch to the desired position to exit the calibration mode.Zone Temperature Lockout: Blanks the display of zone temperature by pressing the RUN button, zone temperature will be re-re-displayed by pressing RUN button once again.Key Pad Lockout: Locks out the programming functions by pressing and holding the “+” & “-” buttons simultaneously untilthe display blanks and returns to normal. To unlock the key pad, repeat the procedure.Adjustable Check Filter Interval (from 10 hours to 59 weeks): This is done by moving the SYSTEM switch to “OFF”, thenpress and continue to hold the CLEAR button, next move the FAN switch to “ON” and then back to AUTO (the CHECKFILTER icon and “0000” hours will appear. Adjust the interval by pressing the “+” or “-” buttons, once completed release theCLEAR button and move the SYSTEM and FAN switches to the desired positions.Intelligent Copy: Allows the program to be copied from one day to another during the initial programming.

Dip switch #1 enables Morning Warm-up, when turned “ON” this will keep the outside air damper closed until zonetemperature is within 2° F. of the occupied heating set point.

Dip switch #2 overrides Minimum Position, when turned “ON” the outside air damper is closed during the unoccupied mode.

Dip switch #3 selects Fahrenheit or Celsius temperature display, when turned “OFF” Fahrenheit is displayed.

Dip switch #4 enables Supply Air Tempering, when turned “ON” supply air temperature is maintained within +10o F. of theheating set point, when in heat mode and not actively heating.

Dip switch #5 selects internal or remote zone temperature sensing, when turned “OFF” internal sensor is used.

Dip switch #6 selects 12 or 24 hour time, when turned “OFF” 12 hour time is displayed.

Dip switch #7 enables the Smart Fan option, when turned “ON” the fan mode is forced to the AUTO mode when the equipmentis in the unoccupied heating or cooling mode.

Dip switch #8 enables Intelligent Temperature Recovery, when turned “ON” the zone will be at occupied temperature at theoccupied time, instead of being in the process of recovering from night set back.

Dip switch #9 is for configuration, reference Installers Guide for specific instructions (SENS-IN-1, 2, or 3).


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6. Microcontrol Accessories and What They Offer

6.1. BAYSENS006B/ASYSTAT661BAccessory Heat / Cool Zone Sensor Module (ZSM), single set point, manual change over. Four conductors required.Manufactured by Sunne, introduced 12/93.


BAYSENS006B [Sunne part# 62822] SEN-0410ASYSTAT661B [Sunne part# 62830] SEN-0417

6.2. BAYSENS007B / ASYSTAT662BAccessory Heat Pump Zone Sensor Module (ZSM), single set point, manual change over. Six conductors required.Manufactured by Sunne, introduced 12/93.




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6.3. BAYSENS008B / ASYSTAT663BAccessory Heat / Cool Zone Sensor Module (ZSM), dual set point, manual / auto change over. Five conductors required.Manufactured by Sunne, introduced 12/93.



6.4. BAYSENS009B / ASYSTAT664BAccessory Heat Pump Zone Sensor Module (ZSM), dual set point, manual / auto change over. Seven conductors required.Manufactured by Sunne, introduced 12/93.




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6.5. BAYSENS010BAccessory Heat / Cool Zone Sensor Module (ZSM), dual set point with LEDs, manual / auto change over. Ten conductorsrequired. Manufactured by Sunne, introduced 12/93.



6.6. BAYSENS011BAccessory Heat Pump Zone Sensor Module (ZSM), dual set point with LEDs, manual / auto change over. Ten conductorsrequired. Manufactured by Sunne, introduced 12/93.




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6.7. BAYSENS013CAccessory ICS (Tracer/Tracker/ComforTrac) Zone Sensor Module (ZSM), with override button, and override cancel button.Two conductors required. Manufactured by Sunne, introduced 08/95.


BAYSENS013C [Sunne part# 65464] SEN-0495

6.8. BAYSENS014CAccessory ICS (Tracer/Tracker/ComforTrac) Zone Sensor Module (ZSM), with override button, set point, and override cancelbutton. Three conductors required. Manufactured by Sunne, introduced 08/95.


BAYSENS014C [Sunne part# 65465] SEN-0496


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6.9. BAYSENS015A Humidity Sensor (OHS, RHS)

Outdoor Humidity Sensor: field installed accessory, located below and to the left of economizer actuator motor. Used inreference (BAYENTH003A) and comparative (BAYENTH004A) enthalpy control.Return Humidity Sensor: field installed accessory, located inside economizer barometric relief hood. Used in comparative(BAYENTH004A) enthalpy control only. (Honeywell #C7600A1028)


BAYSENS015A Humidity Sensor (OHS, RHS) SEN-0277

6.10. BAYSENS016A Thermistor Sensor (OAS, SAS, RAS, CTS)

Outdoor Air Sensor: located in corner post by unit control box, standard on all microcontrol units.Supply Air Sensor: field installed in supply fan housing, comes standard with all microcontrol economizer accessories, andBAYDIAG001A (Generic Input/Output Module) used to gain additional points on ICS jobs when economizers are not used.Return Air Sensor: field installed accessory. Located in barometric relief hood of economizer accessory, used in comparativeenthalpy control only (BAYENTH004A accessory).Coil Temperature Sensor: located in a 3/8" copper tube well, which is brazed to the lowest circuit entering the outdoor coil,during the heating mode (3-7.5 ton heat pumps only).


Thermistor Sensor (OAS, SAS, RAS) SEN-0339


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6.11. BAYSENS017B / ASYSTAT669AAccessory Zone Sensor Remote, used with all current zone sensors. Two conductors required. Manufactured by Sunne,introduced 12/93.


BAYSENS017B [Sunne part# 62828] SEN-0435ASYSTAT669A [Sunne part# 65541] SEN-0493

6.12. BAYSENS019B / ASYSTAT666B

Accessory Heat/Cool, programmable night set back Zone Sensor Module (ZSM), with LCD status / diagnostic indicators. Sevenconductors, terminals 11, 12 & 14 required, 7 through 10 optional. Manufactured by Heatcraft, introduced 06/98.


BAYSENS019B [Heatcraft part# 91K91] SEN-0874ASYSTAT666B [Heatcraft part# 91K92] SEN-0907


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1.1.5. BAYSENS019B Options Menu1. Morning Warm-up: The option (when enabled) will activate the heat if the zone temp is below HSP, whenever thesystem is switched from unoccupied to occupied mode.

2. Economizer Minimum Position Override: The option (when enabled) will override the min. position in unoccupiedmode and close the economizer damper.

3. Temperature Scale: This option changes temp. scale from degrees F to degrees C.

4. Supply Air Tempering: The option (when enabled), if the SAT reaches 10 degrees below the HSP (heat will beenabled), until the SAT reaches 10 degrees above the HSP. Heat will be OFF at this point.

5. Time Clock: An option for 12 hr. or 24 hr. time.

6. Smart Fan: When enabled puts the fan in Auto Mode during unocc. periods regardless of the fan switch position.

7. Intelligent Temperature Recovery: This option (when enabled) automatically computes when to turn on system sothat comfort temp. is efficiently recovered by the start of the occupied period.

8. Programmable Days/Weeks: This option allows the user to select the days of the week for programming. (7,5,2,1)

9. Programmable Periods/Day: This option allows the user to choose the number of events per day.

10. Programmable Fan Operation: This option (when enabled) allows the user to program the fan mode for eachevent/period. (This overrides Smart Fan Option 6)

11. Remote Sensor: This option should be enabled whenever using an optional remote sensor.

12. Check Filter Interval: This option allows the user to set an interval to check the filters on a regular schedule.(Check: filter icon will alarm after the set amount of run hrs., disable the alarm icon by pressing ERASE key)

13. Display Zone Temperature: This option allows the user to display the current zone temp or display a blank zonetemperature.

14. Keypad Lockout: This option allows the user to enable the keypad lockout function. (Lockout keypad bypressing “+” and “-“ keys simultaneously for 4 sec.)

15. Initial Time Setting in Temporary Override: This option allows the user to have a preset time when initialoverride is started.

16. Buzzer Option: This option enables the buzzer alarm for the different settings. (Check Filter, System Failures)

17. Zone Temperature Calibration: This option allows the user to calibrate the zone temperature with any offsets.(Hold the +/- key for 2 sec. to change temperature setting)

18. Baud Rate: This option is the communication speed. For units/UCP’s built before 1/96 change this option to 0.

19. CV or HP Operation: Changes the sensor to a Heat Pump sensor. (CV =Gas or Electric. HP =Heat Pump.)

20. Default Cooling Setpt: If the program is erased or not programmed, this option will go to the default set point.

21. Default Heating Setpt: If the program is erased or not programmed, this option will go to the heat default setpt.

22. Minimum Cooling Set point: This option limits the Cooling Set point to a minimum and maximum range.

23. Maximum Heating Set point: This option limits the Heating Set point to a minimum and maximum range.


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6.13. BAYSENS020BAccessory Heat/Cool, programmable night set back Zone Sensor Module (ZSM) for VAV applications, with LCD status /diagnostic indicators. Seven conductors, terminals 11, 12 & 14 required, 7 through 10 optional. Manufactured by Heatcraft,introduced 06/98.


BAYSENS020B [Heatcraft part# 91K93] SEN-0874

1.1.6. BAYSENS020B Options Menu

1. Morning Warm-up: This is an option (when enabled) will activate the heat if the zone temp is below HSPwhenever the system switched from unoccupied to occupied mode. 2. Econ. Minimum Position Override: This is an option (when enabled) that will override the min. position inunoccupied mode and close the econ. dmpr. 3. Temp. Scale: This is an option that changes temp. scale from degrees F to degrees C.

4. Heat Installed: This option transmits the heat installed bit status in the configuration data to the UCP. If disabled,the MODULATING HEAT option is ignored and default set points are sent to the UCP for Warm-up, Supply-AirHeat, and Unoccupied Heat. The Program Review Menu will not offer selections for these set points if disabled.

5. Time Clock: This is an option for 12 hr. or 24 hr. time.

6. Modulated Heat: When enabled, the supply air heat set point is offered to be programmed by the user. Ifdisabled, the default supply air heat set point will be transmitted.

7. Daytime Warm-up: This option transmits the daytime warm-up bit status in the configuration data to the UCP.The UCP then calculates when to enable/disable daytime warm-up.

8. Programmable Days/Weeks: This option allows the user to select the days of the week for programming. (7,3,2,1)

9. Programmable Periods/Day: This option allows the user to choose the number of events per day.

10. Remote Sensor: This option should be enabled whenever using an optional remote sensor.

11. Check Filter Interval: This option allows the user to set an interval to check the filters on a regular schedule.(Check filter icon on the sensor will alarm after the set amount of run hrs., disable the alarm icon by pressingERASE key)

12. Display Zone Temp.: This option allows the user to display the current zone temp or display a blank zone temp.


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13. Keypad Lockout: This option allows the user to enable the keypad lockout function. (Lockout keypad bypressing + and - keys simultaneously for 4 sec.)

14. Default Time Setting in Temporary Override: This option allows the user to have a preset time when initialoverride is started.

15. Buzzer Option: This option enables the buzzer alarm for the different settings. (Key press only, Check Filter,System Failures)

16. Zone Temperature Calibration: This option allows the user to calibrate the zone temperature with any offsets.(Hold the +/- key for 2 sec. to change temperature setting)

17. Default Cooling Set point: This option is for if the program is erased or not programmed it will default to this setpoint in unoccupied mode.

18. Default Heating Set point: This option is for if the program is erased or not programmed it will default to this setpoint in unoccupied mode.

19. Default Supply Air Cool: This option is for set points which are transmitted to the UCP. These defaults are usedin special situations where either the user has left the set point blank.

20. Default Supply Air Heat: This option is for set points which are transmitted to the UCP. These defaults are usedin special situations where either the user has left the set point blank.

21. Default Warm-up: This option is for set points which are transmitted to the UCP. These defaults are used inspecial situations where either the user has left the set point blank.

22. Minimum Cooling Set point: This option is to limit the CSP to a minimum range.

23. Maximum Heating Set point: This option is to limit the HSP to a maximum range.

24. Minimum Supply Air Cool: This option is to limit the Supply Air Cooling to a minimum range.

25. Maximum Supply Air Heat: This option is to limit the Supply Air Heating to a maximum range.

26. Maximum Warm-up: This option is to limit the Warm-up to a maximum range.


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6.14. BAYSENS021B

Accessory Zone Sensor Module (ZSM) for VAV applications, single set point with LEDs, system auto or off. Nine conductors,terminals 1, 2, 3, & 4 required, 6 through 10 optional.


BAYSENS021A SEN-0440

6.15. Electronic Time Clock

The BAYCLCK001A / ASYSTAT668A has a 16 digit LCD display and provides set up / set back for multiple units (up tofour), when used in conjunction with a standard zone sensor module (see YC-EB-1 for sequence of operation details). Theelectronic time clock is a true 7 day programmable device which offers one occupied and one unoccupied mode per day, and asmart copy feature allows Monday’s program to be copied to every other day (upon initial power up).

The time clock contains four separate relays with normally open contacts, each set of contacts would be wired to terminalsLTB-11 and LTB-12. The normally open contacts may be used to power an auxiliary relay and control any generic buildingdevice or load. The time clock requires 24 VAC provided by unit terminals LTB-16 and LTB-20 (or LTB-15 and LTB-16 onequipment produced prior 07/93).


BAYCLCK001A TWR-0115ASYSTAT668A TWR-0116

6.16. High Temperature Sensor


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The high temperature sensor accessory (BAYFRST001A) provides high limit cutout with manual reset in ICS device Tracer /Tracker / ComforTrac / VariTrac warm air or air conditioning systems. The sensors are wired in series to the TraneCommunications Interface (TCI).

Note: These accessories can also be applied in Non-ICS applications and wired between terminals LTB-16 and LTB-17 at thelow voltage terminal strip.

The sensors may be used to detect heat from a fire in air conditioning or ventilation ducts and provide system shut down tocontain the fire. Approximately 30 seconds after a sensor opens, the associated unit will completely shut down. The sensorscome with case and cover, and mount directly to the duct work. There are two sensors that are included in the accessory. Bothsensors are factory set, one opens at 135° F. and should be installed in the return air duct, the other opens at 240° F. and shouldbe installed in the supply duct.

To reset a sensor which has opened, push and release the button protruding through the cover. See reset button. The sensortemperature must drop 25° F. below the cut out point before it will reset.There are no field adjustments that can be made to the sensor, if a problem exists, the sensor must be replaced.Part Number "CNT-0637" = 135° F. sensor.


BAYFRST001A CNT-0637


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Section 2

7. Start Up From The Unit "Test Mode Feature"

7.1. Step Test ModeUtilizing the sight hole in the lower left-hand corner of the of the control box front panel, verify that the LED on the UCP isburning continuously. (The cover panel does not require removal.)

Initiate the test mode by shorting across the "TEST" terminals on the unit’s Low Voltage Terminal Board (LTB) for two tothree seconds, and then removing the short. The LED on the UCP will blink indicating the unit is in the test mode, and theindoor fan motor (IDM) is turned on (STEP1). The unit may be left in any step for up to one hour to allow for troubleshooting.If left in any one mode, after approximately one hour, the UCP will exit the test mode.

To step into the next mode, short across the "TEST" terminals, and remove the short. See test mode table. The UCP will skipthe steps marked with *, or **, if they are not a feature or accessory on this unit. Exit the test mode by cycling unit power withthe disconnect switch (off & on), or by stepping through the test steps, until the UCP’s LED burns continuously.

7.2. Auto Test ModeThis test mode is the most useful during initial system start up. The entire duration of the test will last from 90-270 secondsdepending on the unit, and accessories installed.

Initiate the Auto Test Mode by installing a jumper across the "TEST" terminals on the unit’s Low Voltage Terminal Board(LTB). The LED on the UCP will begin to blink, indicating the unit is in the test mode. The unit will cycle through the teststeps in sequence, one time, changing test steps every 30 seconds.

The UCP will skip the steps marked with *, or **, if they are not a feature or accessory on this unit. Terminate the Auto TestMode by removing the jumper from the "TEST" terminals, and cycling the unit power with the disconnect switch (off & on). Ifthe unit is inadvertently left in the Auto Test Mode, with the jumper in place across the "TEST" terminals. The UCP willautomatically exit the test mode, and ignore the jumper across the "TEST" terminals.

7.3. Resistance Test ModeThis test mode is used to force the unit into a specific test step, a selection of resistors or a decade resistor box(BAYSERV001A) is required, takes the guess work out of which test step unit is in.

Initiate the Resistance Test Mode by installing the proper resistor across the "TEST" terminals on the unit’s Low Voltageterminal Board (LTB). The LED on the UCP will begin to blink, indicating the unit is in the test mode, and the system willoperate in the desired mode.

Terminate the Resistance Test Mode by removing the resistor from the "TEST" terminals, and cycling the unit power with thedisconnect switch (off & on). If the unit is inadvertently left in the Resistance Test Mode, with the resistor in place across the"TEST" terminals. The UCP will automatically exit the test mode after one hour, and ignore the resistor across the "TEST"terminals.


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7.4. Test Mode Voyager 3-25


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7.5. VAV Test Mode Voyager 27.5-50TEST MODE IGV/VFD FAN ECON COMP COMP HEAT HEAT OHMSSTEP (Note 7) (Note 6) 1 2 1 2

1 IGV/VFD TEST OPEN/100% OFF CLOSED OFF OFF OFF OFF 2.2K2 IGV/VFD TEST CLOSED/OF

FOFF CLOSED OFF OFF OFF OFF 3.3K

3 MINIMUM (Note 1) IN MINIMUMVENTILATION CONTROL ON POSITION OFF OFF OFF OFF 4.7K

4 ECONOMIZER (Note 1) INCONTROL ON OPEN OFF OFF OFF OFF 6.8K

5 COOL (Note 1) IN (Note 2) MINIMUM (Note 4)STAGE 1 CONTROL ON POSITION ON OFF OFF OFF 10K

6 COOL (Note 1) IN (Note 2) MINIMUM (Note 5) (Note4,5)

STAGE 2 CONTROL ON POSITION OFF ON OFF OFF 15K7 COOL (Note 1) IN (Note 2) MINIMUM (Note 4) (Note 4)

STAGE 3 CONTROL ON POSITION ON ON OFF OFF 22K8 HEAT (Note 1) (Note 2) (Note 3)

STAGE 1 OPEN ON CLOSED OFF OFF ON OFF 33K9 HEAT (Note 1) (Note 2) (Note 3) (Note 3)

STAGE 2 OPEN ON CLOSED OFF OFF ON ON 47K10 RESET

7.6. CV Test Mode Voyager 27.5-50

TEST MODE FAN ECON COMP COMP HEAT HEAT OHMSSTEP (Note 6) 1 2 1 2

1 MINIMUM MINIMUMVENTILATION ON POSITION OFF OFF OFF OFF 4.7K

2 ECONOMIZERTEST OPEN ON OPEN OFF OFF OFF OFF 6.8K

3 COOL MINIMUM (Note 4)STAGE 1 ON POSITION ON OFF OFF OFF 10K

4 COOL MINIMUM (Note5) (Note 4,5)STAGE 2 ON POSITION OFF ON OFF OFF 15K

5 COOL MINIMUM (Note 4) (Note 4)STAGE 3 ON POSITION ON ON OFF OFF 22K

6 HEATSTAGE 1 ON CLOSED OFF OFF ON OFF 33K

7 HEATSTAGE 2 ON CLOSED OFF OFF ON ON 47K

8 RESETNotes:1 - The IGV will be controlled to the supply pressure set point unless test mode has been running for 6 minutes or Longer then IGV damper will drive to the full open position.2 - The supply fan will not be allowed to go from an off state to an on state until the IGV are fully closed.3 - The Heat outputs will not be allowed to come on until the IGV are at the full open position.4 - The condenser fans will operate any time a compressor is ON providing the outdoor air temperatures are Within the operating values listed.5 - For 27.5 thru 35 Ton units, cool stage 2 is not used and cool stage 3 becomes the active sequence.6 - The exhaust fan will turn on anytime the economizer damper position is equal to or greater than the exhaust fan set point.7 - The VAV box output will be energized at the start of the test mode to allow time for the boxes to open. It takes 6 minutesfor the boxes to drive from the full closed position to the full open position. The timing cannot be changed in the field.


42

7.7. UCP Default Control

If the UCP loses communication with an ICS device, or if it loses the Zone Sensor Module’s Heating and Cooling set pointinput (slide potentiometers), the UCP will control to the default mode within approximately 15 minutes.

The temperature sensing thermistor in the Zone Sensor Module is the ONLY component required for the Default Mode tooperate. (Without knowing the zone temperature, constant volume units will not heat or cool.)

Comfort can be provided without a Zone Sensor Module by removing the Outdoor Air Sensor from the machine and connectingit in the room to the wires from LTB-1 and LTB-2. This can also be done on the roof, by connecting the sensorto LTB-1 and LTB-2, and dropping it in the return air stream. Note: A jumper is required for default operation on 27.5-50 tonVAV between LTB1-2 and LTB1-4.

1.1.7. Constant Volume 3-50 Ton

Component or Function Default OperationCooling Set point (CSP) 74° F.Heating Set point (HSP) 71° F.Economizer Normal OperationEconomizer Minimum Position Normal OperationMode Normal operation, or auto if ZSM mode switch has failedFan Normal operation, or continuous if fan mode switch on ZSM has

failedNight Setback Mode Disabled - Used with Tracer, Tracker, ComforTrac &

Programmable ZSMs onlySupply Air Tempering Disabled - Used with Tracer, Tracker, ComforTrac, Digital &

Programmable ZSMs onlyPower Exhaust Enable 25% or higher outdoor air opening

1.1.8. VAV 27.5-50 Ton

Component or Function Default OperationSupply Air Cooling Setpt. 55° F.Supply Air Reset Setpt. Disable ResetSupply Air Reset Amount Disable ResetSupply Air Static Setpt. 0.5 IWCSupply Air Static Deadband 0.5 IWCMorning Warm-Up Setpt. Disable MWU & DWUMode Failure “Open” Unit Mode “Off”Mode Failure “Shorted” Unit Mode “Auto”


43

7.8. Providing Temporary (default) Heating And Cooling

Voyager Constant Volume Units

Locate the hole in the corner post, next to the control box. Remove the thermistor sensor (OAS), by reaching around and behindthe corner post, slide it out of the rubber grommet. Cut the two (2) splices and remove the sensor. Using two (2) wire nuts,individually cap the wires remaining in the control box. Note: Voyager 27.5-50 Tons- The OSA Sensor is located below theeconomizer damperhood.

Locate the Low Voltage Terminal Board (LTB) on the right side of the control box, and connect two (2) thermostat wires fromdown in the room to terminals LTB-1 and LTB-2. Take the sensor removed from the unit, and connect it with wire nuts down inthe room, to the two (2) wires that are connected to terminals LTB-1 and LTB-2 at the unit.

The indoor fan will run continuously, and economizer minimum position (if present) will operate. The constant volume coolingset point will be 74° F, and the heating set point will be 71° F. The system will run in the auto mode and switch between heatingand cooling as necessary. Units for Variable Air Volume applications only require a jumper between terminals LTB-2 andLTB-4 for “Supply Air” cooling operation. If unoccupied heating and cooling is required, follow the constant volumeprocedure above.

Note: This is for temporary operation only. Economizer, condenser fan cycling, and evaporator defrost functions are disabled.Evaporator will freeze during low ambient cooling.


44

7.9. Tracer / Tracker / ComforTrac / Comfort Manager

The UCP in the microcontrol unit acts as a slave device to an Integrated Comfort System (ICS) device, the microcontrol unitoperation is dictated by the ICS device. The ICS device can dictate modes of operation, however it cannot override the inherentequipment protection and efficiency timings which are built into the UCP. The respective modes of operation are identical tothose in s 60-63.

When the microcontrol unit is energized, it will take anywhere from one to two minutes for the UCP to take the ICS device setpoints. In the mean time the equipment may begin to start up in the stand alone mode. On a typical VariTrac CCP or ComfortManager installation, there is no Zone Sensor Module connected to the microcontrol unit, the microcontrol unit will sit idleuntil it receives its commands from the Comfort Manager. A microcontrol unit Zone Sensor Module can be connected to theunit, so that in the event of a Comfort Manager failure, it will provide stand alone operation and control. For more in depthinformation on an ICS device, consult the specific ICS device literature.

Note: VariTrac can not be applied with 27.5-50 ton VAV units. It only works with constant volume units.


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8. LED Locations and Status Information

8.1. Unitary Control Processor LED

ON-Indicates that the UCP is powered up, also indicates that the software/computer program is intact and functional, and is lit continuously during normal operation.BLINKING-Indicates that the UCP is in the TEST mode.OFF-Indicates that no power is going to the UCP, or that the software/computer program has failed.

8.2. Unitary Economizer Module LED

ON-Indicates that the UCP is sending a signal to drive the economizer actuator (ECA) motor open or closed. Lit only when the damper should be opening or closing.Note: During economizer calibration, typically at initial power up, the UCP will close the damper and over drive forapproximately 1 to 1.5 minutes. The LED on the UEM will be lit, but the damper will not be moving.OFF-Indicates UCP is "not" sending a signal to drive the economizer actuator motor open or closed. The damper should not be moving.


46

8.3. TCI-1 - LED

ON-Indicates that communication is taking place between the UCP and ICS device, ICS device is transmitting data to the UCP,LED is not continuously lit but actually blinking at a nearly imperceptible rate.OFF-Indicates communication is "not" presently taking place.

8.4. TCI-2 And 3 - LED

TX (TRANSMIT) RED LEDON-Indicates Comfort Manager is transmitting data to the UCP. LED is not continuously lit but actually blinking at a nearly imperceptible rate.OFF-Indicates Comfort Manager is "not" transmitting data to the UCP at this time.

RX (RECEIVE) GREEN LEDON-Indicates Comfort Manager is receiving data from the UCP. LED is not continuously lit but actually blinking at a nearly imperceptible rate.OFF-Indicates Comfort Manager is "not" receiving data from the UCP at this time.Note: The frequency at which communication takes place is a function of the ICS Device, refer to ICS device literature.


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9. Cooling Start Up From The Zone Sensor Module (ZSM) Or Thermostat

9.1. Cooling Mode

1.1.9. Cooling Staging 3-25 Tons

Stage 1 3 minutes OFF minimum 3 minutes ON minimum OFF

Stage 2 3 minutes OFF minimum 3 min. delay between stages 3 minutes ON minimum OFF

Indoor Fan OFF ON OFF

Outdoor Fan 1 OFF ON OFF

Outdoor Fan 2 OFF ON above 65° F. OFF

0 1 2 3 4 5 6 7 8 9 10 11 12Time Progress by Minutes

1.1.10. Cooling Staging 27.5-50 TonsUnit Size Tons Stage 1 Stage 2 Stage 3 Condenser Fan

Output ACondenser FanOutput B

OA Temp.Fans “OFF”

27.5-30 CPR1 *

CPR1, 2 NA

Fan #2

Fan#2Fan #3

Fan #3

7090-1060

35 CPR1 *

CPR1, 2 NA

Fan #2

Fan#2Fan #3

Fan #3

6585-2055

40 CPR 1 **

CPR 2, 3***CPR1,2,3

Fan #2

Fan #2

Fan #2

Fan # 3,4

Fan #3,4

Fan #3,4

50702060-3050

50 CPR1 **

CPR 2,3 ***

CPR 1,2,3

Fan #2

Fan #2

Fan #2

Fan #3,4

Fan #3,4

Fan #3,4

2060-1055-30-30

* Single circuit, dual manifolded compressors** First Stage, Number one refrigeration circuit, Stand alone compressor is “On”.*** First Stage is “Off”, number two refrigeration circuit, manifolded compressor pair operating simultaneously is “On”.


48

Cooling Mode Constant Volume Notes for Voyager 3-50 Tons:

1. Sensor or thermostat settings should be set in the following positions.• Set the fan switch to auto and the system switch to cool.• Set the cooling set point at least 3° F. below the space temperature.

2. At power up the UCP self tests for 20 seconds before beginning compressor timing.

3. Each compressor will be off for a minimum of 3 minutes before beginning a cycle, and will run for a minimum of 3minutes before ending a cycle.

4. There will be a minimum of 3 minutes delay between compressor stages turning ON, beginning with VI & VIIsoftware.

5. When the fan switch is in the auto position, the indoor fan continues to operate for 60 seconds after the completion of acooling cycle, to increase efficiency by removing residual cooling from the DX coil/ CV only (3-50 tons).

6. At power up the economizer goes through a calibration cycle. It will drive open for 5 seconds and then drive closed for 90 seconds, verifying damper is fully closed.

7. If a CTI and a thermostat are being used, and an economizer is present, the economizer calibration sequence must be complete before the fan can be turned on by the fan switch at the thermostat (CV only 3-50 tons).

8. The compressor cooling control loop was changed from 90 to 10 seconds beginning with VI & VII software, (06/93).

Cooling Mode Variable Air Volume Notes for Voyager 27.5-50 Tons:

VAV Cooling staging is the same as constant volume staging. The fan is on all the time, and IGV’s or VFDcontrols amount of airflow.


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9.2. Economizer Operation 3-50 ton Constant Volume Units

The typical setup of the microcontrol 0 to 100% fully modulating economizer includes the following:• Actuator motor (ECA)• Unitary Economizer Module (UEM),• Unitary Control Processor (UCP),• Supply Air (temperature) Sensor (SAS).

On a call for cooling, providing outdoor air conditions are suitable to economize, the Unitary Control Processor (UCP) willprovide 2 functions.1. The UCP will sub-cool the zone to a point between 0.5 and 1.5° F. below the physical zone sensor module’s (or ICS

device) cooling set point.2. The UCP will maintain a 50 to 55° F. supply air temperature.

If the supply air temperature is above 55° F., the UCP will open the outside air damper to admit additional outdoor air until thetemperature returns to the 50 to 55° F. range. If the supply air temperature is below 50° F, the UCP will close the outside airdamper until the temperature returns to the 50 to 55° F. range. Note: If there is not an active call for cooling, providing theindoor fan motor is operating, the UCP will have the outdoor air damper positioned in the minimum ventilation position.

Economizer 3-25 tons

Economizer 27.5-50 tons


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9.3. Dry Bulb Change Over - Field SelectableThe dry bulb change over point is the outdoor temperature at which the equipment will change over, on a temperature fall, frommechanical to economizer cooling. Like wise, the system will change back over, from economizer cooling to mechanicalcooling, if the outside air temperature rises above the selected change over temperature. There are 3 selectable dry bulb changeover points. The two switches referenced are located on the UEM board, they are on the left hand side of the board. Selectingthe proper dry bulb change over point is typically relative to the geographic location of the job site. For example, we may selecta 65° F. change over point for an arid climate like Arizona or California, and a 55° F. change over point for a more humidclimate like Georgia or Virginia. The lower the humidity, the more comfortable the zone will be (typically 50% relativehumidity or less). The lower the change over point, the more comfortable the customer will be. The higher the change overpoint, the more economical the operation will be.

Dry Bulb Change Over- Field Selectable

9.4. Single Enthalpy "Reference" Change Over - Field Selectable

Reference enthalpy is accomplished by using the BAYENTH003A accessory, consisting of an Outdoor Humidity Sensor(OHS). Similar to single enthalpy control, it is selectable to one of 4 enthalpies. If the outdoor enthalpy is greater than 1/2Btu/LB dry air above the selected enthalpy, the economizer will not operate and will not open past minimum position. Theeconomizer will not operate at outdoor temperatures above 75° F., the humidity sensor maximum operating limit.

If the outdoor enthalpy is less than 1/2 Btu/LB dry air below the selected enthalpy, the microcontrol equipment will changeover, from mechanical to economizer cooling utilizing outdoor air. Mechanical cooling will operate if the outdoor enthalpyrises 1/2 Btu/LB dry air above the selected enthalpy.

There are 4 field selectable reference enthalpy change over points. The two switches referenced are located on the UEMboard, they are on the left hand side of the board. The switches are factory set at “D”, this is the most comfortable, not the mosteconomical setting. If a failure occurs in this switching circuit, the enthalpy change over point will default to setting “C”. If theOutdoor Humidity Sensor (OHS) or Unitary Economizer Module's (UEM's) input for this sensor were to fail, the economizerwill operate using Dry Bulb Change Over.


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9.5. Differential Enthalpy "Comparative" Change Over

Comparative enthalpy is accomplished by using the BAYENTH004A accessory, consisting of an Outdoor Humidity Sensor(OHS), Return Humidity Sensor (RHS) and Return Air (temperature) Sensor (RAS). Similar to differential enthalpy control,used in electromechanical equipment. If the outdoor enthalpy is greater than 1/2 Btu/LB dry air above the return air enthalpy,the economizer will not operate and will not open past minimum position. The economizer will not operate at outdoortemperatures above 75° F., the humidity sensor maximum operating limit.

If the outdoor enthalpy is less than 1/2 Btu/LB dry air below the return air enthalpy, the microcontrol equipment will changeover, from mechanical to economizer cooling utilizing outdoor air. Mechanical cooling will operate if the outdoor enthalpyrises 1/2 Btu/LB dry air above the return air enthalpy. If the Return Air Sensor (RAS) or the Return Humidity sensor (RHS)were to fail, the economizer will operate using Reference Enthalpy. If the Outdoor Humidity Sensor (OHS) were to fail, theeconomizer will operate using Dry Bulb Change Over.


52

9.6. Economizer And Options 3-50 ton Constant Volume Units

Addition of economizer preferred cooling logic on all equipment produced after 06/93, X13650473 (BRD-0931) UCP. Thisallows fully integrated economizer operation, where under extreme cooling requirement periods, the compressor(s) can operatein conjunction with the economizer if needed.

A 3 minute delay evaluates and verifies the Zone Temperature is dropping. A compressor will not be turned on if the zone isrecovering at a rate of 12° F./hour (0.2° F./minute). Compressor 1 will be turned “ON” to assist the economizer, providing theoutside air damper has driven 100% open, and the zone temperature (after 3 minutes) is not dropping at a rate of 12° F./hour(0.2° F./minute).

System Where Zone Temperature Recovery Is Satisfactory

System Where Zone Temperature Recovery Is Unsatisfactory


53

9.7. Economizer Set Point- Constant Volume (3-50 tons)The economizer set point is a minimum of 1.5° F. above the heating set point, the control algorithm will not let it be any closer.The economizer set point is also a maximum of 1.5° F. below the cooling set point, the control algorithm will not let it be anyfarther. The cooling and heating set points can be as close together as 2° F. , and as far apart as 40° F. the economizer set pointchanges as the cooling and heating set point changes.

The economizer set point is a variable depending upon how close the heating and cooling set points are in relationship to oneanother. The economizer set point can be as close as 0.5° F. below the cooling set point, but no further than 1.5° F. below thecooling set point. When the heating and cooling set points are only 2° F. apart, the 1.5° F. minimum above the heating set pointforces the economizer set point to 0.5° F. below the cooling set point. When the set points are 3° F. apart or farther, theeconomizer set point is at its maximum of 1.5° F. below the cooling set point.

9.8. Economizer Set Point- Variable Air Volume (27.5-50 tons)The following is dependent upon economizer and compressor deadbands and set points for VAV units. See example below:1. If suitable to economize and the outside air temperature is less than the Economizer Deadband Lower Limit (EDBLL)

(which means <53.5°F from example below), then Mechanical cooling is disabled. If outside air temperature is greaterthan or equal to EDBLL (which means > or = 53.5°F from example below), Mechanical cooling is enabled.

2. If outside air temperature is greater than EDBLL (53.5°F) and the supply air temperature is greater than the EconomizerDeadband Upper Limit (EDBUL) (which is 56.5 °F from example below), the economizer damper will modulate to 100%.

3. After the economizer reaches 100% and conditions are still suitable to economize, 1 compressor is turned on.4. If this is still not reaching supply air (SA) cooling set point (55°F) and it is still suitable to economize, then mechanical

cooling is enabled.


54

9.9. How The Economizer Functions Electrically

1.1.11. How The UCP Receives Information To Make Control DecisionsThe UCP has only 1 analog input that goes out to the UEM, however the UEM has 8 different inputs going to it that the UCPmust read. This information gets back to the UCP in a unique manner, via the U1 chip on the UEM, by using logic gatetechnology. What this boils down to, is that the UCP outputs on terminals J2-10, J2-11, and J2-12 can be viewed as single polesingle throw (SPST) switches of sorts.

By changing the position of the switches, and coming up with different combinations, the UCP is capable of toggling the U1chip and reading all 8 UEM inputs through 1 UCP input. These 3 "switches" are capable of making up 8 different combinations.Each combination then in turn completes a circuit, allowing the UCP to read all 8 UEM inputs through 1 wire, one at a time.As the switches at the UCP change state from "OFF" (Logic Level Low 0VDC) to "ON" (Logic Level Hi +5VDC) and back,the U1 chip of the UEM changes position and makes contact with each UEM input as the UCP tells it to.

UEM Inputs UEM U1 Chip UCP

Outdoor Relative Humidity (J9)Return Relative Humidity (J7) 2 1Supply Air Sensor (J2-1) 3 �J1-4� � J2-15 Analog Com LinkReturn Air Sensor (J3-1) 4

� �J1-5� � � J2-10 (0 VDC)Minimum Position Pot. (J11) 5 �J1-6� � � J2-11 (+5 VDC)Defrost Input (J4-2) 6 �J1-8� � � J2-12 (0 VDC)UEM Switch 1 & 2 (N/A) 7 8Active Fan Fail Switch (J5-3)

1.1.12. How The UCP Causes Changes To OccurThe UCP processes the information it receives through the UEM to make control related decisions, like whether to economizeor not, or whether to drive the damper motor (modulate) open or closed to lower or raise the supply air temperature.

To drive the damper motor open, the UCP sends 5 volts DC out through terminal J2-8, the 5 volts DC enters the UEM atterminal J1-11, where it energizes an electronic device (similar to a relay) to complete an electrical circuit. This makes aconnection between the UEM terminal J5-8 and the common side of the control power transformer, to drive the damper motoropen. To drive the damper motor closed, the UCP sends 5 volts DC out through terminal J2-9, the 5 volts DC enters the UEMat terminal J1-10, where it energizes an electronic device (similar to a relay) to complete an electrical circuit. This makes aconnection between the UEM terminal J5-7 and the common side of the control power transformer, to drive the damper motorclosed.

Transformer (TNS1)l 24 VAC l

ECA UEM UCP

TR � J5-5

TR1 � �J5-7 J1-10 Close +5V

CW � � � � � J2-9J5-8 J1-11

CCW � � � � � J2-8Open +5V


55

10. Heating / Cooling Change OverThe change over from heating to cooling is accomplished in two different manners. The device which causes the difference inchange over point is the economizer. The first drawing below illustrates change over in a system without an economizer, andsecond drawing illustrates change over in a system with an economizer. Change over from cooling to heating is accomplished inthe same manner for both economizer and economizer less systems.

If the unit is in the cooling mode and the zone temperature is falling, the unit will change to the heating mode when the zonetemperature is equal to or less than the heating set point. For systems without economizers, if the unit is in the heating mode,and the zone temperature is rising, the unit will change to the cooling mode when the zone temperature is equal to or greaterthan the cooling set point. For systems with economizers, if the unit is in the heating mode, and the zone temperature is rising,the unit will change to the cooling mode when the zone temperature is equal to or greater than the economizer set point.

ZTEMP ZTEMP falling falling

CSP CSP Change To Cooling

ESP Change To

Change To Change To Cooling Heating Heating

HSP HSP ZTEMP ZTEMP rising rising


56

11. Gas Heat Start Up From The Zone Sensor Module (ZSM) Or Thermostat

11.1. Gas Heat Mode (Constant Volume 3-50 tons)

1st Stage - Lo Fire OFF ON OFF

2nd Stage - Hi Fire OFF ON OFF


Igniter Probe ON OFF

Gas Valve OFF ON OFF

0 1 2 3 4 5 6Minutes

If the zone temperature is more than 0.3° F. above the Heating Set Point, all heat should be off, providing all timingrequirements have been met. As the zone temperature drops, when it is between 0.1- 0.3° F. below set point, stage 1 heat willbe turned on. If the zone temperature continues to fall, stage 2 heat (if present) will be turned on approximately 0.75° F. belowset point.

The graph above illustrates the gas heating mode start up sequence. The various operating components are down the left side,and time progresses left to right across the graph.

Gas Heating Mode Constant Volume - Voyager 3-50 Tons:

Assume the:1. Sensor or thermostat is set in the following positions.

• The fan switch in auto and the system switch in heat.• The heating set point at least 3° F. above the space temperature (Constant Volume).

2. At power up the UCP self tests for 20 seconds before beginning heating timing.3. The heat cycle will start in 2nd Stage - Hi Fire for 30 seconds, after which time it will go to 1st Stage - Low Fire. If

2nd Stage - Hi Fire is required, it will stage up again to 2nd Stage - Hi Fire.4. A 7 second trial for ignition occurs 45 seconds into the heat cycle, lock out occurs after 3 unsuccessful trials.5. 45 seconds after the heating cycle is initiated, the indoor fan will be turned ON, allowing time for the heat exchanger

to warm up, so that cold air is not blown onto the occupants of the space.6. The indoor fan operates for 90 seconds after each heat cycle when the fan switch is in the auto position, to remove

any residual heat left in the heat exchanger.7. If a CTI and thermostat are used, the heat cycle can be initiated and terminated as rapidly as every 5 seconds.8. At power up the economizer goes through a calibration cycle. It will drive open for 5 seconds and then drive closed

for 90 seconds, verifying damper is fully closed.9. If a CTI and a thermostat are being used, and an economizer is present, the economizer calibration sequence must be

complete before the heating cycle can begin or the fan can be turned on by the fan switch at the thermostat.10. A 4 minute minimum ON time existed for the gas heat cycle, and the control loop was changed from 90 to 10

seconds in X13650473 software (06/93). (Voyager 3-25 tons) 11. The 4 minute minimum ON time could be defeated in X13650508 software (06/94) (Voyager 3-25 tons).12. The 4 minute minimum ON time was removed in X13650564 software (Voyager 3-25 tons).

Gas Heating Mode Variable Air Volume - Voyager 27.5-50 Tons:


57

1. Morning Warm-up is enabled when the following occurs (CV or VAV):• The local MWU set point is in range• Enabled through the remote panel with night setback or ICS enabled.

MWU is activated whenever the unit switches from unoccupied to occupied and the zone temperature is at least a1.5°F below the MWU set point. When MWU is activated the system will ensure that the VAV boxes have beensignaled to be open for at least 6 minutes after which the IGV or VFD will be driven to full air flow. After theprevious conditions have been met, all stages of gas or electric heat shall be energized and the economizer dampershall be driven fully closed. To reduce the effect of rapid building temperature swing, heat will be cycled betweenheat stages 1 & 2 in response to a calculated set point which approaches the MWU shall terminate and all stages ofheat shall be de-energized. The unit shall switch over to VAV cooling operation, after the zone temperature risesabove the MWU set point.

2. Daytime Warm-up (DWU) is enabled through the following (VAV Only):• An ICS device• Night setback zone sensor• J1-3 in unit wiring harness

The unit is shipped form the factory with a VAV panel which has a MWU set point potentiometer. Daytime warm-up set pointis 3°F below the MWU set point set at the VAV panel, programmable zone sensor, or ICS device. Daytime warm-up isactivated when the unit is in the occupied mode and the zone temperature is below the daytime warm-up initiate temperature orthe unit is in occupied heat mode. DWU is deactivated when the zone temperature reaches the MWU set point.


58

12. Electric Heat Start Up From The ZSM Or Thermostat

12.1. Electric / Electric Heat Mode (Constant Volume 3-50 tons)

1st Stage Heat OFF ON OFF

2nd Stage Heat OFF ON OFF


0 5 10 15 20 25 30 35 40 45 50Second

The graph above illustrates electric heating mode start up sequence. The various operating components are down the left side,and time progresses left to right across the graph.

Electric Heating Mode Constant Volume - Voyager 3-50 Tons:

Assume the:1. Sensor or thermostat is set in the following positions:

• The fan switch in auto and the system switch in heat.• The heating set point at least 3° F. above the space temperature.

2. At power up the UCP self tests for 20 seconds before beginning heating timing.3. There is an additional 10 second delay before starting the first stage of electric heat, and a 10 second delay between

stages. Minimum on and off times are 10 seconds. 30 seconds will elapse before first stage heat turns on.4. The indoor fan will start one second before first stage electric heat is energized, when heat cycle ends, indoor fan is

turned off at the same time as electric heat.5. If a CTI and thermostat are used, the heat can be turned on and off as rapidly as every 5 seconds.6. At power up the economizer goes through a calibration cycle. It will drive open for 5 seconds and then drive

closed for 90 seconds, verifying damper is fully closed.7. If a CTI and a thermostat are being used, and an economizer is present, the economizer calibration sequence must be

complete before the heating cycle can begin or the fan can be turned on by the fan switch at the thermostat.8. The heating control loop was changed from 90 to 10 seconds beginning with X13650473 software, (06/93)

(VI & VII).

Electric Heating Mode Variable Air Volume - Voyager 27.5-50 Tons:

Refer back to Gas Heat for CV and VAV Morning Warm-up & VAV Daytime Warm-up Control.


59

13. Heat Pump Start Up From The ZSM Or Thermostat

13.1. Heat Pump Heating Mode (3-20 tons) WC Units

CPR1 & CPR2 ON OFF

1st Stage Aux. OFF ON OFF

2nd Stage Aux. OFF ON OFF

Indoor Fan ON OFF

ODF1 & ODF2 ON OFF

SOV(s) OFF (Except when in Cooling mode or Defrost)

0 2 4 6 8 10 12 14 16 18 20 22 24Minutes

The graph above illustrates heat pump heating mode start up sequence. The various operating components are down the leftside, and time progresses left to right across the graph.

Heat Pump Heating Mode Constant Volume Notes Voyager 3-20 Tons::

Assume the:1. Sensor or thermostat is set in the following positions.

• The fan switch in auto and the system switch in heat.• The heating set point at least 3° F. above the space temperature.

2. At power up the UCP self tests for 20 seconds before beginning compressor timing.3. Each compressor will be off for a minimum of 3 minutes before beginning a cycle, and will run for a minimum of 3

minutes before ending a cycle.4. Both compressors operate as first stage heating. There is a one second delay between starting compressors.5. A 9 minute delay exists between heat stages, between 1st stage auxiliary/mechanical, and 2nd/1st stage auxiliary.6. At power up the economizer goes through a calibration cycle. It will open for 5 seconds and then drive closed for 90

seconds, verifying damper is fully closed.7. If a CTI and a thermostat are being used, and an economizer is present, the economizer calibration sequence must be

complete before the fan can be turned on by the fan switch at the thermostat.


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14. Low Ambient Mechanical Cooling Operation

14.1. Evaporator Defrost Control (EDC) Function (3-25 Tons only)

The Evaporator Defrost Control (EDC) function provides low ambient cooling, standard, down to 0° F. At this temperature, theequipment can provide approximately 60% of the mechanical cooling capacity. During low ambient operation compressor runtime is counted and accumulated by the UCP. Low ambient operation is defined as 55° F. for single condenser fan units (3through 10 ton), and 40° F. for dual condenser fan units (12 1/2 through 25 ton). Dual condenser fan units are capable ofproviding condenser fan cycling.

When accumulated compressor run time reaches approximately 10 minutes, an evaporator defrost cycle is initiated. Anevaporator defrost cycle lasts for 3 minutes, this matches the compressor 3 minute minimum OFF time. When an evaporatordefrost cycle occurs, the compressors are turned off and the indoor fan motor continues to run. After completing an evaporatordefrost cycle the unit returns to normal operation, and the compressor run time counter is reset to zero.

Note: Economizer operation is not affected by an evaporator defrost cycle.

Compressor |← OFF →|← ON (10 minute accumulated compressor run time) →|← OFF →|← ON →

Indoor Fan |← OFF →|← ON (Continues to run even with fan selector switch set in Automatic position →| | | | | | | | | | | | | | | | | | |

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18Minutes

27.5-50 Ton Frostat Trip (CV and VAV)

The Frostat input is a normally closed binary input.

Upon sensing a continuous open state on the frostat input for 5 seconds nominal the following will occur:

1. Both compressors are to be turned off after they have been operating for a minimum of 3 minutes continuous operation.2. Supply fan will be forced ON until frostat input has been in a continuously closed state for 5 seconds nominal or 60

seconds after the call for cooling is satisfied, which ever is longer.

Note: Frostat opens at 35° F. plus or minus 5° F.


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15. Defrost Operation

15.1. Demand Defrost

Demand Defrost is used on 3-7 1/2 Ton Heat Pumps, the UCP logic supports both Demand and Time / Temperature defrost, theUCP determines defrost operation by configuration wires built into each unit wiring harness. Similar to Tyler Demand Defrostoperation, however defrost is allowed below 6° F. outdoor temperatures if needed. After 30 minutes of run time under defrostpermit conditions the UCP will initiate a defrost cycle. Data gathered during this cycle will be used to calculate clean coil deltaT and defrost initiate value.

Upon termination of this cycle, the UCP monitors outdoor temperature (ODT) and coil temperature (CT) and calculates delta T(ODT-CT), this value is stored in memory and the UCP calculates a defrost initiate value. The UCP is continually comparingdelta T to the defrost initiate value. To permit defrost, outdoor temperature must be below 52° F., coil temperature must bebelow 33° F. and delta T must exceed calculated value. After delta T reaches current initiate value, a defrost cycle will begin.

Defrost Termination is calculated in the following manner:Defrost Termination Temperature (DTT) = Outdoor Temperature (ODT) + 47° F. or, DTT = ODT + 47° F.The DTT will typically be between 57° F. and 72° F

15.2. Demand Defrost Failures, Diagnostics, and Defaults

The following is a complete listing of the failures or operating problems, and defaults for stand alone system operation withZone Sensor Modules (ZSM’s). An ICS device Tracer / Tracker / ComforTrac will directly indicate any of the items below,immediately after the first occurrence.

Problem = Coil Temperature Sensor (CTS) FailureDiagnostic = (Simultaneous Heat And Cool Fail At ZSM Or LTB)Default = 10 Minute Defrost After Each 30 Minutes Of Accumulated Compressor Run Time

Problem = Outdoor Air Sensor (OAS) FailureDiagnostic = (Simultaneous Heat And Cool Fail At ZSM Or LTB)Default = 10 Minute Defrost After Each 30 Minutes Of Accumulated Compressor Run Time

Problem = Mode Switch In Emergency Heat PositionDiagnostic = (Heat Fail At ZSM Or LTB)Default = Mechanical (Compressor) Heating Disabled, Auxiliary Heat Only

Problem = Low Delta T For 2 Hours (Tyler Fault A)Diagnostic = (Simultaneous Heat And Cool Fail At ZSM Or LTB)Default = 10 Minute Defrost After Each 30 Minutes Of Accumulated Compressor Run Time

Problem = 10 Consecutive Defrosts Terminated By Time (Tyler Fault B)Diagnostic = (Simultaneous Heat And Cool Fail At ZSM Or LTB)Default = 10 Minute Defrost After Each 30 Minutes Of Accumulated Compressor Run Time

Problem = 16 Consecutive High Delta Ts After Defrost (Tyler Fault C)Diagnostic = (Simultaneous Heat And Cool Fail At ZSM Or LTB)Default = 10 Minute Defrost After Each 30 Minutes Of Accumulated Compressor Run Time


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15.3. Time Temperature Defrost

Time / Temperature Defrost

Switch Switch Defrost SOVs |← OFF →|← ON →|←OFF 1 2 Time

Selected Defrost Time Interval = 45 MinutesOFF OFF 70 Min. DT Switch |←OPEN→|← CLOSED →|←OPENON OFF 90 Min. | | | | | | | | | | | | |OFF ON 60 Min 0 5 10 15 20 25 30 35 40 45 50 55 60ON ON 45 Min. Minutes

Time / Temperature Defrost uses the Defrost Module (DFM), which is located in the control box, used in 10-20 ton heat pumpunits only. It provides the temperature input to the UCP for Time / Temperature defrost.

The defrost interval is field selectable to one of four settings, factory and default setting is 70 minutes. See 76. After thecompressor(s) have accumulated the run time selected on the Defrost Module (DFM), and the Defrost Temperature Switch(DT) closes, the UCP initiates outdoor coil defrost.

The defrost cycle ends when the DT changes to the "open" state, or after approximately 10 minutes of defrost, or high pressurecontrol on either compressor opens.

15.4. Time / Temperature Defrost Failures, Diagnostics, and Defaults

If the UCP sees an out of range temperature / resistance from the Defrost Module due to an open or shorted circuit, a 10 minutedefault defrost cycle will be initiated by the UCP after each 70 minutes of accumulated compressor run time.

A failure of this type will cause the HEAT and COOL LEDs to blink at the Zone Sensor Module (if applicable) once persecond. This will also indicate a simultaneous HEAT and COOL failure at the low voltage terminal board LTB. As long as theon board relay on the Defrost Module, and it’s controlling circuitry remain intact to energize the Switch Over Valve(s) SOV(s),defrost will still occur.

15.5. Soft Start

DT Switch |← CLOSED →|← OPEN (Defrost cycle terminating) →|

↓ 5 second Soft Start delay ↓

SOV(s) |← ON →|← OFF →|

Outdoor Fan(s) |← OFF →|← ON →|| | | | | | | | | | | | | | | | | | |

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18Seconds

The UCP has a built in “Soft Start” feature which is utilized in heat pump operation only. When a Heat Pump defrost cycle isterminating, the outdoor fan(s) are turned on for 5 seconds before de-energizing the switch over valve(s). "Soft Start" providesa smooth transition back to mechanical heating operation, and minimizes noise associated with switch over valve operation.This feature also improves compressor reliability, by greatly reducing stress on compressors associated with high pressuredifferential during defrost.


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15.6. Smart Recovery

The UCP has built in Heat Pump "Smart Recovery", if the heat produced by the compressor(s) is making a recovery toward setpoint at a rate of at least 6° F./hour (0.1° F./minute), the electric heat is not turned on. A nine minute stage up delay allows timefor recovery to begin. Every nine minutes after the mechanical heating cycle starts, the UCP checks the zone temperature to seeif it is rising at least 6° F./hour (0.1° F./minute). If it is, auxiliary electric heat is not turned on, and the UCP continues the nineminute monitoring process.

If the zone temperature is not rising at a rate of at least 6° F./hour (0.1° F./minute), the UCP will energize the first stage ofauxiliary electric heat (if installed). The UCP continues the nine minute monitoring process, if the zone temperature is still notrising at least 6° F./hour (0.1° F./minute), the second stage of auxiliary electric heat is energized (if installed). If after the nextnine minute interval the zone temperature is rising sufficiently, the UCP will de-energize the second stage of auxiliary electricheat, and continue to stage down in reverse order.

Temperature °F. Temperature °F.75.0 75.0 Zone74.9 74.9 Temperature →74.8 ← Zone 74.874.7 Temperature 74.774.6 74.6 ↑74.5 74.5 Stage 1 Auxiliary Turned “ON” | | | | | | | | | | | | | | | | | | | | | | | | | | | | 0 1 2 3 4 5 6 7 8 9 10 11 12 13 0 1 2 3 4 5 6 7 8 9 10 11 12 13 Minutes Minutes

16. Operation with a Conventional Thermostat Interface (CTI)

When a Conventional Thermostat Interface (CTI) is applied, equipment operation differs significantly. The basic equipmentprotection features remain intact, and the following features and benefits are lost:

• Direct Digital Control- Proportional Integral (PI) control is lost, equipment is controlled by a thermostat or genericbuilding automation system device.

• On Board Diagnostics are lost, they are still available at the Unitary Control Processor (UCP) level on the J7 junction pins,but are no longer accessible at the Low Voltage Terminal Board (LTB).

• Intelligent Fall Back is lost, if a failure occurs in the device controlling the equipment, operation will cease.• Heat Pump Smart Recovery And Smart Staging is lost, Heat Pump operation becomes more costly unless generic control being applied can accomplish this.• Remote Sensing Capabilities are lost.• Space Temperature Averaging capabilities are lost• Supply Air Tempering Features feature is lost, discharge air temperature may be cold when not actively heating if outdoor

air is being introduced through the equipment.• Built in Night Set Back and Unoccupied Functions are lost.• Built in Unoccupied mode is lost• Economizer Preferred Cooling is lost. (Prior to 10/97)

Note: Installation is more costly. In addition to the price of Conventional Thermostat Interface and the thermostat or genericcontrol, the control wiring size must be increased.


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17. Power Exhaust

Power Exhaust 3-25 Ton Units:The power exhaust can be installed on 6.25-25 ton (and 5 ton High Efficiency) downflow units when an economizer accessoryis used or to return duct work 3-25 ton for horizontal units. Note: Make sure the power exhaust is braced properly.

The power exhaust is typically used to help alleviate building pressurization, it should not be substituted for a separate exhaustsystem when one is needed or required. Pressurization problems will occur on extremely tight buildings, with multiple rooftopunits with economizers and power exhaust, if a separate exhaust system is not installed.

Under normal design conditions, +0.25" w.c. return building static, the power exhaust is capable of exhausting approximately30% of nominal system air flow. See catalog for specific unit data. Performance will vary as system design deviates fromtypical conditions. The more negative the return static, the less air it is capable of exhausting.

The power exhaust fan motor is energized when the damper is at a position greater than 25% of the actuator stroke. If minimumposition is above 25%, after a 22.5 second delay for damper to reach 25% on the way to minimum position, power exhaust willoperate each time the indoor fan is energized. If minimum position is below 25%, power exhaust will operate only when theunit is economizing and the damper is open more than 25%.

Note: The Exhaust Fan Contactor (XFC) has a 30 VDC coil.

Power Exhaust 27.5-50 Ton Units:The 27.5 – 50 ton power exhaust fan is started whenever the position of the economizer dampers meets or exceeds the powerexhaust set point when the supply fan is running. The set point panel is located in the return air section. This power exhaustcan be adjusted from low to high speed or medium if 1 fan is wired for low & 1 for high speed.

Under normal design conditions, +0.25" w.c. return building static, the power exhaust is capable of exhausting approximately50% of nominal system air flow. See catalog for specific unit data.


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Section 3

18. Electrical Measurements

18.1. With Plugs ConnectedWhile trouble shooting the microcontrol units, there will be times when it is necessary to make electrical measurements with thesystem powered up and operating. There are several different methods of accomplishing. Electronic meter lead accessory kitsare commercially available for this purpose, and make the servicers job easier.

An alternative to this is to utilize two small paper clips, with one end straightened. These are small enough to be slid into theconnector along side the wire, and make contact with the internal terminal, without causing any damage. A multimeter can nowbe connected to the two paper clips, allowing the electrical measurements to be made.

Note: Do not puncture the wire insulation with meter leads to make electrical measurements.

18.2. With Plugs DisconnectedWhile trouble shooting the microcontrol units, there will be times when it is necessary to make board level electricalmeasurements. The proper test clip leads are the "Mini Grabber / Plunger Type" test clips. These leads must be capable ofgrabbing a 0.045" square terminal, with a center to center terminal distance of 0.156".

The Mini Grabber/Plunger Type test clips can effectively be clipped to the UCP board terminals. Do not attempt to utilizealligator test clips, or any general purpose test clips to accomplish this type of measurement. Test clips other than MiniGrabbers do not have the proper clearance capabilities, and short circuits will occur, resulting in P.C. board failures.


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18.3. At Disconnected Plug EndsWhile trouble shooting the microcontrol units, there will be times when it is necessary to make electrical measurements, and testthe terminal integrity at the disconnected plug ends. Electronic meter lead accessory kits are available for this purpose.

An alternative to these kits is to utilize two small paper clips, with one end straightened. Paper clips are small enough that theycan be slid into the plug end of the connector, and make contact with the internal terminal, without causing any damage. If theinternal terminal grips the paper clip, without the clip falling out, the terminal is usually alright. A multimeter can now beconnected to the two paper clips, allowing the electrical measurements to be made. Do not force the probe end of a standardmeter lead into the plug end of the connector to make electrical measurements. This will damage the terminals, causing loss ofcontact, and leave you with more problems than you had originally.

19. Trouble Shooting From An Integrated Comfort System (ICS) DeviceAn ICS device like: Tracer, Tracker/ComforTrac (CV only), and Comfort Manager(CV only), is an effective means of locatingthe source of a problem. There are 46 or more Binary and Analog values, some standard and some accessory achieved, on amicrocontrol unit that can be accessed on site or remotely. This allows diversity in being able to diagnose and trouble shoot, orchecking system status on several pieces of equipment from just one location.

Several of the values will alarm the ICS device in the event of a failure, and through custom alarming, those that do not may beenabled to do so. Trend logs can be set up to monitor most of these points at regular intervals, so that suspect problemoccurrences can be captured and viewed, without having to continuously monitor system status. If a modem is installed in theICS device, countless hours of manpower can be saved in travel, trouble shooting can begin immediately after an alarm ortelephone call is received. Consult the respective ICS device Installation / Operation / Programming (IOP) manual forinformation on programming and set up.


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20. Recommended Steps For Trouble Shooting

Step 1. Do Not kill unit power with disconnect switch, or diagnostic & failure status information will be lost.Step 2. Utilizing the hole in the lower left hand corner of the control box dead front panel, verify that the LED on the UCP isburning continuously. If LED is lit, go to Step 4.Step 3. If LED is not lit, verify presence of 24 VAC between LTB-16 and LTB-20 (Note: LTB-16 and LTB-18 before 06/93).If 24 VAC is present, proceed to Step 4. If 24 VAC is not present, test unit primary voltage, test transformer (TNS1) and fuseor internal circuit breaker, test fuse (F1) in upper right hand corner of UCP. Proceed to Step 4 if necessary.Step 4. Utilizing the Failure Status Diagnostics at the end of this section, test the following: System status, Heating status, andCooling status. If a Heating failure, a Cooling failure, or both are indicated, follow instructions in Failure Status Diagnosticssection. If a System failure is indicated, proceed to Step 5. If no failures are indicated, proceed to Step 6.Step 5. If a System failure is indicated, re-check Steps 2 and 3. If the LED is not lit in Step 2, and 24 VAC is present in Step 3,the UCP has failed. Replace UCP.Step 6. If no failures are indicated, place the system in the test mode, utilizing the Test Mode Feature in Section 2. Thisprocedure will allow you to test all of the UCP’s on board outputs, and all of the off board controls (relays, contactors, etc.) thatthe UCP outputs energize, for each respective mode. Proceed to Step 7.Step 7. Step the system through all of the available modes, and verify operation of all outputs, controls, and modes. If aproblem in operation is noted in any mode, you may leave the system in that mode for up to one hour while troubleshooting.refer to sequence of operations for each mode, to assist in verifying proper operation. Make repairs if necessary, and proceedto Steps 8, and 9.Step 8. If no abnormal operating conditions appear in the test mode, exit by cycling unit power at the service disconnect. Thisverifies that all of the UCP’s on board outputs, and all of the controls the UCP’s outputs energize are operational.Step 9. Refer to Individual Component Test Procedures in Section 4, if other microelectronic components are suspect.


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21. Trouble Shooting Chart “Problem Descriptions And Causes”

Note: Always verify the unit is operating in the proper "MODE" when troubleshooting.

SYMPTOM PROBABLE CAUSE RECOMMENDED ACTION

A. Unit will not operate. 1. No power to the Unit. 1. Check line voltage at service disconnect. No Heat, No Cool or No 2. No power to the UCP. 2. Check for 24 VAC from bottom of F1 fuse to system ground. Fan operation. 3. UCP fuse (F1) is defective. 3. Check for 24 VAC from top of F1 fuse to system ground. If 24VAC is

not present, replace F1 fuse. 4. Zone Temperature Sensor 4. See Zone Sensor Module (ZSM) Test Procedures or short MODE (ZTS) is defective or MODE input on VAV units. circuit is open.5. UCP is defective. 5. If 24 VAC is present at the top of F1 fuse to ground, the LED on the

UCP should be on. If the LED is not lit, replace the UCP. 6. Supply Fan Proving (SFP) 6. Check the IDM and belts, replace as necessary. switch has tripped.7. External Auto/Stop input is 7. Check the External Auto/Stop input. open.

CV Units Only1. Zone Sensor Module (ZSM) 1. Refer to the Zone Sensor Module (ZSM) Test Procedures.

B. Unit will not Heat or is defective. Cool, but the Fan 2. Problem in (ZSM) wiring. 2. Verify all terminal connections between LTB1 and the ZSM are switch operates. properly wired. Disconnect the ZSM wiring at LTB1 and test the

wires using the Zone Sensor Test Procedures to locate any wiring problems.

3. UCP is defective. 3. Disconnect connector P7 from the UCP and perform the Zone Sensor Module (ZSM) Test Procedures. If within range, replace UCP.

CV or VAV (Unoccupied)1. Zone Sensor Module (ZSM) 1. Refer to the Zone Sensor Module (ZSM) Test Procedures.

C. Unit heats and cools, is defective. Possible Cool Refer to the Unit Control Processor (UCP) Default Chart. but will not control to Failure set point. 2. Thermometer on the ZSM 2. Check and calibrate the thermometer.

out of calibration.

D. CPR1 will not operate, 1. Compressor failure. 1. Test compressor, mechanically and electrically. Replace if necessary. ODM’s will operate. 2. Wiring, terminal, or 2. Check wires, terminals and CC1. Repair or replace if necessary.

mechanical CC1 contactor failure.3. LPC1 has tripped 3. Leak check, repair, evacuate and recharge as necessary.

Check LPC1 operation.

E. CPR1 operates, 1. ODM has failed. 1. Check ODM’s, replace if necessary. ODM’s will not operate. 2. ODM capacitor(s) has failed. 2. Check ODM capacitors, replace if necessary.

3. Wiring, terminal, or 3. Check wires, terminals ,CC1 and CC2. Repair or replace if necessary. mechanical CC1 or CC2 contactor failure.4. ODF1 or 2 relay has failed 4.Check for proper voltage and contact closure. ODF1 has a 24 VAC

holding Coil and ODF2 relay has a 24 VDC holding coil. If applicable voltage is present, replace relay.

5. UCP is defective 5. Locate the P1 connector on the UCP. Check for 24 VDC between terminals P1-11 and P1-12. If 24 VDC is not present, replace UCP.

F. CPR1 and ODM1 will 1. No power to CC1 coil. 1. Check wiring, terminals and applicable controls (CCB1, HPC1 not operate. Possible Cool Failure WTL1, LPC1)

2. CC1 coil defective. 2. Check CC1 coil. If open or shorted, replace CC1. Cool Failure Indicated.3. CC1 contacts defective. 3. If 24 VAC is present at CC1coil, verify contact closure.4. UCP is defective. 4. If 24 VAC is not present at CC1 coil, reset the Cool Failure by cycling

the main power disconnect switch. Verify system MODE is set for cooling operation. If no controls have opened, and CC1 will not close, replace UCP.

5. LPC1 has tripped 5. Leak check, repair, evacuate, and recharge as necessary. Check LPC1 operation.


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G. ODM 3 and/or 4 will 1. OAS 1. Perform OAS Resistance/Temperature check. Replace if necessary. not cycle. 2. ODM3 and/or 4 capacitor 2. Check ODM capacitor, replace if necessary.

has failed.3. Wiring, terminal, or CC2 3. Check wires, terminals, and CC2. Repair or replace if necessary. contactor failure.4. ODM3 and/or 4 has failed. 4. Check ODM, replace if necessary.5. UCP is defective. 5. replace UCP module6. ODF2 has failed. 6. Check for proper voltage and contact closure. ODF2 relay has a

24 VDC holding coil. If voltage is present, replace relay.

H. CPR2 and 3 (if 1. No power to CC2 and/or 3 1. Check wiring, terminals and applicable controls (CCB2, CCB3, HPC2, applicable) will not coil. Cool Failure Possible. LPC2, WTL2, WTL3) operate. 2. CC2 and/or 3 coil defective. 2. Verify integrity of CC2 and/or 3 coil windings. If open or shorted

Cool Failure Indicated. replace CC2 and/or CC3.3. CC2 and/or 3 contacts 3. If 24 VAC is present at CC2 and/or 3 coil, replace relay. defective.4. UCP is defective. 4. 24 VAC is not present at CC2 and/or 3 coil. Reset the Cool Failure by

cycling the service disconnect. Place the unit into Cool Stage 2 Mode, step 4 for constant Volume or step 6 for variable air volume, to insure CPR2 and 3 Compressor operation. Check input devices in #1 & #2 above, if no controls have opened, and CC2 and/or 3 will not close, replace UCP.

I. Indoor motor (IDM) 1. IDM has failed. 1. Check IDM, replace if necessary. will not operate 2. Wiring, terminal, 2. Check wiring, terminals and F contactor. Repair or replace wiring,

or contactor failure. terminals, or fan contactor F.3. ZSM is defective. 3. Place unit in test mode. If the fan operates in the test mode, test the

ZSM using the appropriate test procedures.4. UCP is defective. 4. Check the UCP fan output. Locate P2 connector, which is connected

to J2 on the UCP. Find wire 64A (Black) and measure voltage to ground. If 24 VAC is not present on a call for fan, replace the UCP.

5. Supply Fan Proving (SFP) 5. Check SFP and belts, repair or replace if necessary. switch has opened

J. No Heat (YC’s only) 1. CFM has failed. 1. Check CFM, replace if necessary. CFM will not run, IP 2. CFM capacitor 2. Disconnect BROWN wires from capacitor, test, and replace if warms up, GV is has failed. necessary. energized, 3. Wiring, or terminal 3. Check wiring, and terminals. Repair, or replace if necessary.

failure. 4. Check for line voltage between terminals 1 & 3 on heat relay. If line 4. Heat relay H voltage is present, contacts are open. Check for 24 VAC at H coil, has failed. replace H if 24 VAC is present.5. TNS2 and/or 3 has failed. 5. Check for 230 VAC at TNS2 and/or 3 secondary, between Y1 and (460/575 V units only) Y2. If 230 VAC is not present, replace TNS2 and/or 3.

K. No Heat 1. TNS2 and/or 3 has failed. 1. Check for 115 VAC at TNS2 and/or 3 secondary, between X1 and X2. (YC’s only) If 115 VAC is not present, replace TNS2 an/or 3. CFM runs, GV 2. Wiring or terminal failure. 2. Check wiring, and terminals. Repair, or replace if necessary. energizes, 3. IGN has failed. 3. Verify presence of 115 VAC at IGN L1 and L2. Check for 115 VAC IP does not between terminals PPM4-1 and PPM4-2, and PPM5-1 and PPM5-2 warm up. (if applicable) in the gas section. If 115 VAC is present for IP warmup,

IGN is OK. If 115 VAC is not present, replace IGN.4. IP has failed. 4. With 115 VAC applied to IP, warm up should take place. Cold

resistance of IP should be a minimum of 50 Ohms. Nominal current should be 2.5 to 3.0 Amps.


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L. No Heat (YC’s only) 1. Wiring or terminal 1. Verify presence of 24 VAC between IGN PWR terminal to ground, if GV does not energize, failure. not present, check wiring and terminals. Repair or replace if necessary. CFM runs, IP warms up 2. IGN has failed 2. Verify presence of 24 VAC between IGN VALVE terminal to ground, if not present replace IGN. 3. GV has failed. 3. Measure voltage between TH and TR on the gas valve (GV). If 24 VAC is present and the GV will not open, replace the GV.

M. Low Heat Capacity 1. CFM has failed. 1. Check CFM, test LO and HI speed windings. Intermittant Heat. 2. UCP is defective. 2. Check UCP K5 relay. Check for K5 coil voltage at solder joints CR16 (YC’s only) above K5 on the UCP. Nominal voltage at the coil is 28 VDC. CFM runs in LO or HI If 28 VDC is present, COM. & N.O. contacts should be closed, speed only, or; may not energizing CFM HI speed windings. If 28 VDC is not present, LO operate at all in one speed should be energized through K5 COM. & N.C. contacts. speed or the other. If voltage contradicts operation, UCP has failed.

N. No Heat (YC’s only) 1. TCO2 has opened. 1. System Status Failure Diagnostic "Fan" selection switch on Heat Failure Indicated. Place the unit in the HeatingTest Mode, steps 6 & 7 for constant the ZSM is in the volume or step 8 & 9 for variable air volume and check the complete "AUTO" position and the heating system for failure. Make necessary repairs or adjustments fan runs continuously. to the unit.

O. No Heat (TE's only) 1. Heater contactor(s) have 1. Check for 24 VAC at AH, BH,CH, and DH contactor coils. If 24 VAC is Electric heat will failed. present on a call for heat, and the contacts do not close, the contactor not operate. has failed.

2. Heater element 2. Check line voltage between the element temperature limit terminals temperature limit(s) is located in heat section. If line voltage is present, the limit is open. open. Repair heating unit, or replace limit(s) as needed.3. Wiring or terminal failure. 3. Check for wiring, or terminal failure in control and power circuit. Repair or replace if necessary.4. Heater Element(s) 4. Check element and circuit integrity. Repair or replace as necessary.has failed. Replace open elements.5. UCP is defective. 5. Check UCP heat outputs. "First stage", locate P1 connector, connected

to J1 on the UCP. Locate wire 65E at terminal P1-22, measure between 65E and ground. If 24 VAC is present, repeat #3 above. If 24 VAC is not present, the UCP has failed. "Second stage", Check UCP K5 relay. Measure from the common terminal on the relay to ground, 24 VAC should be present, if not repeat #3 above. If present, measure from the N.O. terminal on the relay to ground. If 24 VAC is not present, the UCP has failed.

P. Evaporator coil 1. System low on 1. Leak check, repair, evacuate, and recharge system as necessary. freezes up during refrigerant charge. low ambient 2. System low on air flow. 2. Check return air for obstruction or dirty filters. Check fan wheels, operation. motors, and belts.

3. Outdoor Air Sensor 3. Check OAS at connector P1 by disconnecting P1 from J1 on the UCP. (OAS) has Failed. Check resistance between P1-15 and P1-16, refer to the Resistance

versus Temperature chart. Replace sensor if necessary.4. FrostatTM has Failed 4. Check Frostat Switch


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Q. Economizer will not 1. Economizer connector not 1. Check connector, and connect if necessary. operate. plugged into unit wiring

harness 2. Economizer Actuator 2. Verify that 24 VAC is present between ECA terminals TR and TR1. (ECA) has failed Jumper TR1 to CCW, economizer actuator should drive open. Jumper

TR1 to CW, economizer actuator should drive closed. If ECA does not drive as specified, replace ECA.

3. Unit Economizer 3. Perform the UEM Test Procedures discussed previously. Module (UEM) has failed. 4. Wiring or terminal failure. 4. Check wiring and terminals. Repair or replace if necessary.5. UCP is defective. 5. Perform the UEM Test Procedures discussed previously.

R. Minimum position 1. Minimum position 1. With the main power off, check the resistance between terminals J11 is at zero, cannot potentiometer has failed. and J12 at the UEM by rotating the on board minimum position be adjusted. Economizer potentiometer knob. Resistance should be 50 to 200 Ohms. still modulates. With power on, DC voltage should measure 0.40 to 1.80 VDC. Also

refer to the UEM Test Procedures discussed previously.

S. Economizer goes to 1. OAS has failed. 1. Check the OAS at connector P1 by disconnecting P1 from J1 on the minimum position, UCP. Check resistance between P1-15 and P1-16, refer to the and will not modulate. 2. SAS has failed. Resistance versus Temperature Chart. Replace sensor if necessary.

2. Check the SAS at connector P12 by disconnecting P12 from J2 on the UEM. "SA" is marked on the side of the board. Check for

resistance between P12-1 and P12-2, refer to the Resistance versus Temperature Chart. Replace sensor if necessary.

T. Economizer modulates, 1. Comparative enthalpy setup, 1. Check the return air sensor (RAS) at connector P13 by disconnecting but system does not RAS or RHS failed. P13 from J3 on the UEM. "RA" is marked on the side of the board. seem to operate as System is operating using Check for resistance between P13-1 and P13-2, refer to the effeciently as in the past. Referance enthalpy Resistance versus Temperature Chart. Replace the sensor

if necessary. Check the return air humidity sensor (RHS) by measuring the operating current at terminals J7 (-), and J8 (+) on the UEM board.

Normal operating current is 4 to 20 milliamps mA. Note: The humidity sensors are polarity sensitive, and will not operate if connected backwards.

2. Referance enthalpy setup, 2. Check the outside humidity sensor (OHS) by measuring the opeating OHS has failed. current at terminals J9 (-), and J10 (+) on the UEM module. Normal System is operating using operating current is 4 to 20 milliamps mA. dry bulb control.3. Comparative enthalpy setup, 3. Perform #2 above. OHS has failed. System is operating using dry bulb control.

U. Power Exhaust will 1. Exhaust motor has failed. 1. Check the exhaust fan motor, and replace if necessary. not operate. 2. XFC has failed. 2. Check the exhaust fan contactor (XFC). Replace if necessary

3. UEM has failed. 3. Perform the UEM Test Procedures discussed previously.4. XFSP has Failed 4. Perform the Exhaust Fan Setpoint Test Procedures discussed

previously.

V. IGV/ VFD will not 1. UVM has Failed 1. Perform the UVM Test Procedures discussed previously. operate properly 2. IGV / VFD has Failure 2. Check the IGV / VFD

3. Setpoint Failure 3. Perform the IGV / VFD Setpoint Test Procedures discussed previously.


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22. Component Failure And Response Chart

COMPONENT FAILURE RESPONSE NORMAL RANGE DIAGNOSTIC

(OAS) Outdoor 1. Economizer in minimum -̂55 to 175 F *NONE* Check at UCPAir Sensor position. Will not 6̂80K to 1.2K connector P1, between

modulate. P1-15 & P1-16.

2. ODM3 will not cycle off -̂55 to 175 F *NONE* Check at UCP (runs continuously) 680K to 1.2K connector for CV

or check at UVM for VAV

(RAS) Return Air 1. Economizer operates 0 to 209 F *NONE* Check at UEMSensor using Reference 90K to 7.1K connector P13, between

Enthalpy P13-1 & P13-2.

(SAS) Supply 1. Economizer in minimum 0 to 209 F CV *NONE*Air Sensor position, will not 90K to 7.1K VAV Cool Fail

modulate.

(OHS) Outdoor 1. Uses Dry Bulb operation 4 to 20 mA *NONE* Check at UEMHumidity Sensor and economizes if 90 to 10% RH J9(-) and J10(+) by

below 60 F DB. Honeywell measuring current draw.C7600A.

(RHS) Return Humidity 1. Economizer operates 4 to 20 mA *NONE* Check at UEMSensor using Referance 90 to 10% RH J7(-) and J8(+) by

Enthalpy. Honeywell measuring current draw.C7600A.

Minimum position 1. Economizer modulates UEM onboard *NONE* Check resistancePotentiometer but minimum posiotion potentiometer range at UEM J11 and J12

stays at zero. 50 to 200 50 to 200 Ohms.Ohms.

Cooling Setpoint 1. Uses HSP and CSP 100 to 900 *NONE* Check at(CSP) for CV CSP= HSP + 4 F or use Ohms terminals 2 and 3 on ZSMZSM slide UCP Default Mode. Use ZSM Testpotentiometer Procedures.

Heating Setpoint 1. Uses CSP and HSP 100 to 900 *NONE* Check at(HSP) for CV HSP= CSP - 4 F. Ohms terminals 2 and 5 on ZSM.ZSM slide Use ZSM Testpotentiometer Procedures.

HSP and CSP for CV 1. Cannot control at ZSM, 100 to 900 Cool Failure Outputare both lost. unit using UCP Default Ohms approx. at LTB1-8 to LTB1-6

Mode Use ZSM Test "COOL" LED Blinks Procedures. at ZSM

*NONE* = No LED indication


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(ZTEMP) Zone 1. No Heating or Cooling -40 TO 150 F CV Cool Failure OutputTemperature Sensor ZTS "Fan" selection 346K to 2.1K at LTB1-8 to LTB1-6CV or VAV during switch operates IDM "COOL" LED Blinks Unoccupied mode. during Unoccupied Mode at ZSM

(TCO1 or TC03) Heat goes off Normally Closed *NONE*High Limit Cutout Temperature varies

by unit.

(TCO2) Fan Failure Heat goes off, IDM runs Normally Closed Heat Failure OutputLimit continuously. Open 135 F at LTB1-7 to LTB1-6

Reset 105 F. "HEAT" LED Blinks at ZSM.

(LPC1) Low Pressure Compressor CPR1 Open 7 PSIG Possible Cool Failure at Control will not operate. Close 22 PSIG. J2-2 to Ground, 0 VAC.

"COOL" LED Blinks at ZSM.

(LPC2) Low Pressure Compressor CPR2 Open 7 PSIG Possible Cool Failure atControl will not operate. Close 22 PSIG. J2-3 to Ground, 0 VAC.Dual Circuits Only "COOL" LED blinks at ZSM.

(CCB1) Compressor CPR1 Normally Closed Cool Failure Outputwill not operate. range varies by unit. at LTB1-8 to LTB1-6

"COOL" LED blinks at ZSM.

(CCB2 or CCB3) Compressor CPR2 or Normally Closed Cool Failure OutputCompressor Overload CPR3 will not operate. range varies by unit at LTB1-8 to LTB1-6


(HPC1) High Pressure Compressor CPR1 Open 425 psig Cool Failure OutputControl will not operate. Close 325 psig at LTB1-8 to LTB1-6


(HPC2) High Pressure Compressor CPR2 or Open 425 psig Cool Failure OutputControl CPR3 will not operate. Close 325 psig at LTB1-8 to LTB1-6


(WTL1) Winding Compressor CPR1 Normally Closed Cool Failure OutputTemperature Limit will not operate. at LTB1-8 to LTB1-6


(WTL2 or WTL3) Compressor CPR2 or Normally Closed Cool Failure OutputWinding Temperature CPR3 will not operate. at LTB1-8 to LTB1-6Limit "COOL" LED blinks at ZSM.(CC1) Compressor Compressor CPR1 Varies by unit Cool Failure OutputContactor will not operate. at LTB1-8 to LTB1-624 VAC coil "COOL" LED blinks at ZSM.

(CC2 or CC3) Compressor CPR2 or Varies by unit Cool Failure OutputCompressor Contactor CPR3 will not operate. at LTB1-8 to LTB1-624 VAC coil "COOL" LED blinks at ZSM.*NONE* = No LED indication


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(CFS) Clogged Filter This input is for "indication" Normal operation = SERVICE LED Switch only and does not effect 0 VAC measured comes on, 24 VAC (Any Generic Normally the normal operation between terminals measured betweenOpen Switch) of the unit. J5-1 and Ground. UCP J5-1 and Ground

Supply Fan Proving Unit will not operate in 0.05" W.G. Service Failure OutputSwitch any mode. Normally Closed at LTB-6 to LTB-10

"SERVICE" LED blinks at ZSM

Static Pressure IGV will not open 0.25 - 4 VDC Heat and Cool FailureTransducer VAV between J8 and J9 Output at LTB-7 to LTB-6 &

on VAV LTB-8 to LTB-6 "HEAT" and "COOL" LED’s blink at ZSM

MWU (VAV) Cannot control from unit 0 - 1000 ohms *NONE*Disable MWU & DWU Approx.

Reset Setpoint (VAV) Cannot control from unit 0 - 1000 ohms *NONE*Disable Reset Approx.

Reset Amount (VAV) Cannot control from unit 50 - 750 ohms *NONE*Disable Reset Approx.

SA Press Setpoint Cannot control from unit 80 - 780 ohms *NONE*(VAV Uses Default Approx

SA Press Deband Cannot control from unit 0 - 1000 ohms *NONE*(VAV) Uses Default Approx.

XFSP Cannot control from unit 100 - 900 ohms *NONE*Uses Default of 25% Approx.

*NONE* = No LED indication


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23. Failure Status Diagnostics

23.1. System LED

ON-Indicates that the UCP is powered up, also indicates that the software/computer program is intact and functional, and is litcontinuously during normal operation.BLINKING -Indicates that the UCP is in the TEST mode.OFF -Indicates that no power is going to the UCP, or that the software/computer program has failed. See “Recommended StepsFor Trouble Shooting”.

23.2. Heat LED

ON-Indicates unit is in the heat mode, and actively heating.BLINKING-Indicates a Heating Failure has occurred.OFF- Indicates that the unit is “not” actively heating.

Heating Failure Causes:1. TCO2 has opened (YCs only) / TC03 (V3 27.5-50 tons).2. ZSM mode switch is in Emergency Heat position (WCs only).


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23.3. Cool LED

ON-Indicates unit is in the cool mode, and actively cooling, economizer or mechanical cooling.BLINKING-Indicates a cooling failure has occurred.OFF-Indicates that the unit is “not” actively cooling.

1. Cooling set point (slide pot) on ZSM has failed. See “Testing The ZSM.”2. Zone temperature thermistor ZTEMP on ZSM failed. See “Testing The ZSM.3. CC1 or CC2 24 VAC control circuit has opened, Check CC1 & CC2 coils, and any applicable control(s) (CCB1, CCB2,COL1, COL2, DTL1, DTL2, HPC1, HPC2, WTL1, WTL2).4. CPR1 or CPR2 DISABLE circuit (LPC) opened, during 3 minute minimum ON time, on 4 consecutive compressor starts.5. Open circuit on programmable sensor terminal 12 at LTB.

23.4. Service LED

ON-Used to indicate clogged filter, indication only.BLINKING-Used to indicate fan failure, shuts unit down.OFF-Neither of the above have occurred, or not being used.

Note: SERVICE LED is a generic indicator, field modifications are necessary.


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23.5. Cool and Heat LED

SIMULTANEOUS BLINKING - External Auto Stop (LTB-16 &17) has opened (27.5-50 ton only) Coil or Outside Air Sensor Failure (WC Only)

23.6. Service and Cool LED

SIMULTANEOUS BLINKING - Static Pressure Transducer Failure (27.5-50 ton VAV only)


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23.7. Service, Cool, and Heat LED

SIMULTANEOUS BLINKING - Supply Air High Limit Duct Static Trip. Manual Reset. (27.5-50 ton VAV only)

24. Failure Status Diagnostics

24.1. System ON = Measure DC volts between terminals LTB-6 & LTB-9

Normal Operation = Approximately 32 VDC.System Failure = Less than 1 VDC, approximately 0.75 VDC. Indicates that no power is going to the UCP, or that thesoftware/computer program has failed. See “Recommended Steps For Trouble Shooting”.Test Mode = Alternates between 32 VDC & 0.75 VDC.


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24.2. HEAT = Measure DC volts between terminals LTB-6 & LTB-7.

Heat Operating = Approximately 32 VDC.Heat Off = Less than 1 VDC, approximately 0.75 VDC.Heating Failure = Alternates between 32 VDC & 0.75 VDC.

Heating Failure Causes1. TCO1 or TCO2 has opened (YCs only).2. ZSM mode switch is in Emergency Heat position (WCs only).

24.3. COOL = Measure DC volts between terminals LTB-6 & LTB-8.

Cool Operating = Approximately 32 VDC.Cool Off = Less than 1 VDC, approximately 0.75 VDC.Cooling Failure = Alternates between 32 VDC & 0.75 VDC.

Cooling Failure Causes:1. Cooling set point (slide pot) on ZSM has failed. See “Testing The ZSM”.2. Zone temperature thermistor ZTEMP on ZSM failed. See “Testing The ZSM”.3. CC1 or CC2 24 VAC control circuit has opened, check CC1 & CC2 coils, and any of the controls below applying to this

unit (COL1, COL2, HPC1, HPC2, DTL1, DTL2, WTL1, WTL2).4. CPR1 or CPR2 DISABLE circuit (LPC) opened, during 3 minute minimum ON time, on 4 consecutive compressor starts.


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24.4. SERVICE = Measure DC volts between terminals LTB-6 & LTB-10.

Clogged Filter = Approximately 32 VDC.Normal Operation = Less than 1 VDC, approximately 0.75 VDC.Fan Failure = Alternates between 32 VDC & 0.75 VDC.

Note: SERVICE is a generic indicator, field modifications are necessary.


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Section 4

25. Testing The Unitary Control Processor (UCP)

25.1. Test Mode Functions Properly but Erratic Normal OperationA situation arises where the equipment functions properly in the Test mode, yet fails to operate properly (or at all) duringnormal operation (not in the Test mode). If the equipment operates properly in the Test mode and not during normal operation,an input problem is present. The equipment will function properly during normal operation as long as it is provided with validinputs. Check for diagnostics at the Zone Sensor Module (ZSM) or Low Voltage Terminal Board (LTB). If any diagnostics arepresent, locate and resolve the problem. Note: Always check for diagnostics prior to initiating the Test mode, or all diagnosticswill be lost.

The Test mode bypasses (ignores) all inputs (even the ZSM), the Test mode will function without a Zone Sensor Modulepresent, simulating normal operation. This verifies most of the UCP software, hardware, and all off board components arefunctional.

A Problem Exists Somewhere Between Point “A” And Point “C”.

25.2. Constant Volume 3-50 TonThe Zone Sensor Module (ZSM) is the primary input, which actually consists of four separate inputs. The four separate inputsare: Cooling Set Point (CSP), Heating Set Point (HSP), Mode, and Zone Temperature (ZTEMP). The Zone Temperature(ZTEMP) is the most critical input, the equipment cannot operate without this input.

Knowing how the Test mode operates, an input problem could be any one of the following:

1. The ZSM has failed.2. The ZSM is mis-wired, check field low voltage wiring and rewire properly if necessary.3. The ZSM field wiring has conductor(s) open, shorted to each other, or grounded to conduit etc. Check field wiring with anohmmeter, repair or replace as necessary.4. Induced AC voltage on ZSM field wiring. If the ZSM is installed in conduit with line voltage wiring it must be removed.Disconnect wires at both ends (at the unit and the sensor), check for AC voltage from each conductor to ground. if more than 6volts AC is present, locate problem source and isolate from control wiring.5. Factory wiring error between the Low Voltage Terminal Board (LTB) and the J7 plug on the Unitary Control Processor(UCP). Remove LTB, check and verify unit wiring against schematic wiring diagram, correct if necessary.

25.3. Variable Air Volume (VAV) 27.5-50 TonUnits that have VAV control, only require a jumper across LTB1-2 & LTB1-4 for supply air cooling operation. If unoccupiedor daytime heating is required a zone sensor must be installed across LTB1-1 & LTB1-2 as well as the jumper across LTB1-2& LTB1-4. LTB1-2 & LTB1-4 is the mode input for the VAV unit, which allows the fan to be in auto mode and the unit to beon. LTB1-1 & LTB1-2 is the zone temperature input for heat.


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25.4. Forcing Condenser Fan Cycling (12.5-25 Ton Only)Condenser fan cycling on dual condenser fan units (12.5-25 Tons), can be tested by taking control of the Outdoor Air Sensor(OAS). Note: If an economizer is installed, it must be disconnected at the polarized plugs prior to performing this test.

Electrically remove the Outdoor Air Sensor (OAS) from the circuit, by cutting the wires at the splices in the lower right handcorner of the control box. Insert a 1/4-watt resistive value in place of the OAS to simulate a low ambient condition (33K-75KOhms). This will simulate an outdoor air temperature between 5° F. and 32° F. Place the unit in the cooling mode, and set thecooling set point to 50° F. Outdoor Motor two (ODM2) will be cycled off, based on the outdoor ambient temperature seen bythe UCP, after controlling the Outdoor Air Sensor (OAS) input. ODM2 will be “OFF” when the Outdoor Air temperature fallsbelow 60° (+/- 2°F)., and “ON” if the temperature rises above 65° (+/- 2°F).

25.5. Forcing Condenser Fan Cycling (27.5-50 Ton)Condenser fan cycling on multiple condenser fan units (27.5-50 Tons), can be tested by taking control of the Outdoor AirSensor (OAS). Note: If an economizer is installed, it must be electrically disconnected prior to performing this test.

Electrically remove the Outdoor Air Sensor (OAS) from the circuit. Insert a resistive value in place of the OAS to simulate alow ambient condition (33K-75K Ohms). This will simulate an outdoor air temperature between 5° F. and 32° F. Place the unitin the cooling mode, and set the cooling set point to 50° F. Reference 1.1.10 for Condenser Fan On and Off Temperatures.

25.6. Forcing Evaporator Defrost Control (EDC) Cycle (3-25 Ton)The Evaporator Defrost Control (EDC) can also be tested by taking control of the OAS.Note: If an economizer is installed, it must be disconnected at the polarized plugs prior to performing this test.

Electrically remove the Outdoor Air Sensor (OAS) from the circuit, by cutting the wires, at the splices in the lower right handcorner of the control box. Insert a 1/4 watt resistive value in place of the OAS to simulate a low ambient condition (33K-75KOhms). This will simulate an outdoor air temperature between 5° F. and 32° F. Place the unit in the cooling mode, and set thecooling set point to 50° F. Evaporator Defrost Control (EDC) will now be activated, and the compressor run time counter willbegin counting and accumulating compressor run time. On 12 1/2 through 25 ton units, Outdoor Motor two (ODM2) will beturned “OFF” since the UCP is sensing a low ambient condition. After approximately 10 minutes, a defrost cycle will beinitiated.

25.7. Forcing Economizer OperationThe function of economizer operation can also be tested by taking control the Outdoor Air Sensor (OAS).Note: Do not disconnect the economizer for this test.

Electrically remove the Outdoor Air Sensor (OAS) from the circuit. Insert a 1/4 watt resistive value in place of the OAS tosimulate a low ambient condition (33K-75K Ohms). This will simulate an outdoor air temperature between 5° F. and 32° F.Place the unit in the cooling mode, and set the cooling set point to 50° F. Compressor(s) may run during extended test periods.If it is warm outside, the outside air damper will probably be fully open, and a 50-55° F. supply air temperature will beattempted to be maintained.If a power exhaust accessory is present, it will be energized whenever the economizer damper is at a position greaterthan 25% of the actuator stroke or the set point set on Voyager (27.5-50).


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26. Testing Zone Sensor Module (ZSM)Note: These first 4 tests are not for programmable models, and are conducted with the ZSM electrically removed from thesystem, unless otherwise noted.

26.1. ZSM Terminal Identification

Terminal # Terminal I.D. Terminal # Terminal I.D.

1 ZTEMP 6 LED COMMON

2 SIGNAL COMMON 7 HEAT LED

3 CSP 8 COOL LED

4 MODE 9 SYS ON LED

5 HSP 10 SERVICE LED


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26.2. Test 1: UCP Zone Temperature Input Test

Voltages are measured with power applied to the equipment and the ZSM wired into the circuit. Voltages may be measured atthe Low Voltage Terminal Board (LTB) on the unit, or at the ZSM in the space.

Zone Temperature (ZTEMP) is measured between terminals 1 & 2 at the ZSM (LTB-1 & LTB-2 at the unit).

The resistance values (OHMs) are measured with the ZSM disconnected and isolated from the Unitary Control Processor(UCP). The resistance may be measured at the ZSM, or the unit LTB, with the J7 plug disconnected on the UCP. The electricalvalues below, directly correspond with a zone temperature, that is interpreted by the UCP.

ZTEMPOHMs Volts ZTEMPOHMs Volts ZTEMP OHMs Volts°F Rx1K DC +/-5% °F Rx1K DC +/-5% °F Rx1K DC +/-5%50 19.96 3.125 64 13.83 2.676 78 9.759 2.246

51 19.43 3.105 65 13.49 2.656 79 9.525 2.227

52 18.92 3.066 66 13.15 2.617 80 9.297 2.188

53 18.42 3.027 67 12.82 2.598 81 9.076 2.168

54 17.94 3.008 68 12.50 2.559 82 8.860 2.129

55 17.47 2.969 69 12.19 2.520 83 8.650 2.109

56 17.02 2.930 70 11.89 2.500 84 8.446 2.070

57 16.58 2.910 71 11.60 2.461 85 8.247 2.051

58 16.15 2.871 72 11.31 2.441 86 8.054 2.012

59 15.74 2.852 73 11.03 2.402 87 7.866 1.992

60 15.33 2.813 74 10.76 2.363 88 7.682 1.953

61 14.94 2.773 75 10.50 2.344 89 7.504 1.934

62 14.56 2.754 76 10.25 2.305 90 7.330 1.914

63 14.19 2.715 77 10.00 2.285


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26.3. Test 2: UCP Cooling and Heating Set point Input Test


Cooling Set point (CSP) is measured between terminals 2 and 3 at the ZSM (LTB-2 & LTB-3 at the unit), and Heating set point(HSP) is measured between terminals 2 and 5 at the ZSM (LTB-2 & LTB-5 at the unit).

The resistance values (OHMs) are measured with the ZSM disconnected and isolated from the Unitary Control Processor(UCP). The resistance may be measured at the ZSM, or the unit LTB, with the J7 plug disconnected from the UCP. Theelectrical values below, directly correspond with a set point temperature, that is interpreted by the UCP.

CSP or OHMs Volts CSP or OHMs Volts CSP or OHMs Volts HSP °F Rx1 DC +/-5% HSP °F Rx1 DC +/-5% HSP °F Rx1 DC +/-5% 50 889 2.34 64 617 1.90 78 344 1.27

51 870 2.31 65 597 1.86 79 325 1.22

52 850 2.29 66 578 1.82 80 305 1.16

53 831 2.26 67 558 1.78 81 286 1.10

54 812 2.23 68 539 1.74 82 266 1.04

55 792 2.20 69 519 1.70 83 247 0.98

56 773 2.17 70 500 1.65 84 227 0.92

57 753 2.14 71 481 1.61 85 208 0.85

58 734 2.10 72 461 1.57 86 188 0.78

59 714 2.07 73 442 1.52 87 169 0.72

60 695 2.04 74 422 1.47 88 150 0.64

61 675 2.00 75 403 1.42 89 130 0.57

62 656 1.97 76 383 1.37 90 111 0.49

63 636 1.93 77 364 1.32


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26.4. Test 3: UCP Mode Input Test


MODE is measured between terminals 2 and 4 at the ZSM (LTB-2 & LTB-4 at the unit).

The resistance values (OHMs) are measured with the ZSM disconnected and isolated from the Unitary Control Processor(UCP). The resistance may be measured at the ZSM, or the unit LTB, with the J7 plug disconnected from the UCP. Theelectrical values below, directly correspond with a MODE that is interpreted by the UCP.

System Fan OHMs Volts System Fan OHMs VoltsSwitch Switch Rx1K DC +5% Switch Switch Rx1K DC +5%

Short to Common 0 0.00 AUTO ON 16.13 2.349

OFF AUTO 2.32 0.565 HEAT AUTO 19.48 2.585

COOL AUTO 4.87 1.056 HEAT ON 27.93 3.028

AUTO AUTO 7.68 1.484 EM HEAT AUTO 35.00 3.289

OFF ON 10.77 1.859 EM HEAT ON 43.45 3.524

COOL ON 13.32 2.113 Open Circuit 8 5.000

26.5. Test 4: LED Indicator Test

If an LED fails it will have no effect on system operation, replacing the ZSM is optional.

Method 1: Test LEDs with ZSM connected and wired to the unit. Test voltages at LED terminals on ZSM. A measurement of32 VDC, across an un-lit LED, means the LED has failed.

Method 2: Test the LED with an analog ohmmeter. Connect ohmmeter across LED in one direction, then reverse the leads forthe opposite direction. The LED should have at least 100 times more resistance in reverse direction, as compared with theforward direction.

High resistance is indicated in both directions the LED is open. Low resistance indicated in both directions means the LED isshorted.


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27. Testing The Programmable Zone Sensor Modules (ZSMs)

Step 1. Disconnect wires from LTB-11 (-) and LTB-12 (+), measure voltage between LTB-11 (-) and LTB-12 (+) , should beapproximately 32 VDC. If no voltage is measured check wiring between UCP and LTB. Note: 24 VAC should be presentbetween LTB-14 and LTB-20.

Step 2. Re-connect wires to terminals LTB-11 (-) and LTB-12 (+), measure voltage again between LTB-11 (-) and LTB-12 (+).Voltage should flash high and low every 0.5 seconds. The voltage on the low end will measure approximately 22 VDC, whilethe voltage on the high end will measure approximately 22 to 42 VDC.

Step 3. Verify all modes of operation, by running the unit through all of the steps in the Test Mode.

Step 4. After verifying proper unit operation, exit the test mode. Turn the fan on continuously at the ZSM, by pressing thebutton with the fan symbol, or turning the fan switch “ON” (whichever is applicable). If the fan comes on and runs continuouslythe ZSM is good. If you are not able to turn the fan on, the ZSM is possibly defective and may need replacing.Note: The BAYSENS019B may need the baud rate changed to 1024 for units built prior to 1/96.

Step 5. Reference Programmable ZSM troubleshooting chart.

Step 6. Prior to condemning programmable ZSM (BAYSENS019A, BAYSENS020A, BAYSENS023A, or ASYSTAT666A orASYSTAT667A), it should be re-initialized by activating its self test feature. This is performed prior to the device leaving thevendor. The self test is initiated by pressing the “RUN”, “MANUAL” and “DAY” buttons simultaneously. The ZSM programwill be cleared and the sensor will have to be re-programmed. Upon completion of the test, a “P” for pass or “F” for fail willappear in the upper left-hand corner of the display, along with the software version number. Press the “CLEAR” button and thesensor will test all of the LEDs and LCD pixels, at the conclusion of the LED/LCD test press “CLEAR” again. The sensor maynow be re-programmed.Note: The BAYSENS019B and 020B do not have this test.


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27.1. Programmable Troubleshooting Chart

Problem Probable Cause

Display does not come on. Check for power at terminals LTB-11 and LTB-14 (24 VAC). Make sure sensor is properly mounted to sub-base.

No communications with unit. Check position of dip switch 9 or option #18 (which ever is applicable). Thisselects unit type. Test voltage between LTB-11 and LTB-12 (range = 22 - 42VDC).

Displayed zone temperature is Follow instructions for zone temperature calibration. Be sure sensor has had timedifferent from actual temperature. to adapt from extreme temperatures.

Displayed zone temperature is 0° F. Check position of dip switch 5 or option #18. This selects local or remote(0° C.) and a COOL FAIL is present. sensor. If remote sensor is installed, check wiring for an open circuit condition

between terminals S1 & S2. If local sensing is selected, the onboard thermistor isopen, replace zone sensor module. The BAYSENS019B/020B will display Shand a cool failure if a short circuit condition exist, or oP if an open circuitcondition exist.

Displayed zone temperature is 99° F. Check position of dip switch 5 or option # 18. This selects local or remote sensor.(38° C.) and a COOL FAIL is present. If remote sensor is installed, check wiring for a short circuit condition between

terminals S1 & S2. If local sensing is selected, the onboard thermistor is shorted,replace zone sensor module.

Zone temperature is not displayed. Zone temperature lockout is enabled. Press RUN button or check option # 13 todisplay temperature.

Unit won’t respond to switches & slides. Keypad lockout is enabled. See installation instructions to disable.

Clock must be reset after power outage. The BAYSENS019A/020A requires 3 hours to fully charge the clock’s backupenergy supply (super capacitor). If the sensor was removed from the sub-base, theclock and day must be reset. On the BAYSENS019B/020B replace the battery.

RUN and MANUAL LEDs are flashing, If the optional status indicators are wired, the RUN LED will be “OFF” whenor are not lit. (BAYSENS019A/020A only) unit power is “OFF”, or when the unit is in the TEST mode. The MANUAL LED

will flash when the zone sensor is in temporary override, and is “OFF” when the zone sensor is in program run mode.

Clock flashes “0:00” at initial power up. Check position of dip switch 6 or option #5 which selects 12 Hour or 24 Hourtime display.

FAN switch is in “ON” position but fan Check position of dip switch 7 or option # 6. This selects Smart Fan option, thisproblem would indicate the system is in the unoccupied mode.

System is operating before programmed Check position of dip switch 8 or option #7 which selects computed recovery.start time (Constant Volume and HeatPump units only).


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28. Testing Unitary Economizer Module (UEM)This series of tests will allow you to diagnose, and determine where, and if a problem exists in the system economizeroperation. Test 1 determines if the problem is in the UCP communicating with the UEM. Test 2 will determine if the problemis in the UEM or ECA. Test 3 is for the UEM’s minimum position potentiometer. Test 4 tests sensor inputs and exhaust fanoutput. Test 5 shows how to test the sensors. Conduct tests in numerical order until the problem is found.

28.1. Test 1: Verifying UCP Communication With UEMStep 1: Using the Test Mode, step the unit into the economizer mode. Verify that the ECA drives fully open (approximately 90seconds). The LED on the UEM burns continuously when the ECA drives open or closed.Step 2: If the ECA is not driving the dampers in Step 1, measure the DC voltage output from the UCP between the UEMconnectors J1-11 and J5-5. The voltage measured while the ECA is driving open should be approximately 1.7 VDC. When the90 seconds have elapsed, and the dampers should be fully open, the voltage will change to approximately 5.0 VDC.

Step 3: Using the Test Mode, step the unit into the Cool 1 mode. The ECA should drive fully closed (approximately 90seconds), then open to the preset minimum position. The LED on the UEM burns continuously when the ECA drives.Step 4: If the ECA is not driving the dampers in Step 3, measure the DC voltage output from the UCP between UEMconnectors J1-10 and J5-5. The voltage measured while the ECA is driving closed should be approximately 1.7 VDC. When the90 seconds have elapsed, and the dampers should be fully closed, the voltage will change to approximately 5.0 VDC.

If the voltages in Test 1 are present, the UCP is operating properly. If the ECA will not drive, the problem is in the UEM orECA, continue to Test 2. If voltages are not present a wire, terminal, or UCP failure has occurred.


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28.2. Test 2: Verifying That The ECA Is FunctionalStep 1: With power applied to the system, in any mode, verify presence of 24 VAC between ECA terminals TR and TR1. If 24VAC is not present, a wiring or terminal problem is present.Step 2: Jumper terminal TR1 to terminal CCW, the ECA should begin to drive open. The dampers should be in the fully openposition after approximately 90 seconds. Remove jumper from CCW terminal.Step 3: Jumper terminal TR1 to terminal CW, the ECA should begin to drive closed. The dampers should be in the fully closedposition after approximately 90 seconds. Remove jumper from both terminals.

If after completing Test 1, and the ECA functions in Test 2, the UEM has failed. Replace UEM. If 24 VAC is present in Step 1,and ECA did not drive as specified in Steps 2 and 3, the ECA is defective. Replace ECA.

STEP 1

28.3. Test 3: Testing The UEM Minimum Position PotentiometerStep 1: With power applied to the system, in any mode, verify the presence of 5.0 VDC at the following two points. Voltage ismeasured at connector J1 on the UEM. Measure between J1-1 and J1-3, then measure between J1-3 and J1-9.If 5.0 (+ 0.25) VDC is not present at these two points, a wire, terminal, or UCP failure has occurred. Check integrity of wiringand terminals, repair or replace if necessary. If no wiring problems are present, replace UCP.


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Step 2: After verifying the voltage presence in Step 1, turn the minimum position potentiometer fully counter clock wise.Measure the DC voltage between UEM terminals J11(+) and J12(-), should be approximately 0.47 VDC.Step 3: Turn the minimum position potentiometer one half turn clock wise, so that the screw driver slot is straight up and down.Measured voltage should be approximately 1.18 VDC.Step 4: Turn the minimum position potentiometer fully clock wise. Measured voltage should be approximately 1.70 VDC.

If correct voltages are measured in Steps 1, 2, 3, and 4, UCP, UEM potentiometer and circuitry are good. If correct voltage ismeasured in Step 1, and not in Steps 2 through 4, replace UEM. Continue to Test 4 if necessary.

28.4. Test 4: Testing Sensor Inputs And Exhaust Fan OutputStep 1: With power applied to the system, turn the ZSM mode switch OFF, and the ZSM fan switch ON. Verify the DCvoltages in the following steps.Step 2: Testing Supply Air Sensor Input. Remove connector J2 on UEM, marked SA on the side of the UEM board.Measure voltage between pins J2-1 and J2-2, voltage should measure 5.0 (+ 0.25) VDC.

If correct voltages are measured in Tests 1 through 3, and voltage in Test 4, Step 2 is out of range, replace UEM.


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Step 3: Testing Return Air Sensor Input. Remove connector J3 on UEM (if installed), marked RA on the side of the UEMboard. Measure voltage between pins J3-1 and J3-2. Voltage should measure 5.0 (+ 0.25) VDC.


Step 4: Testing Active Fan Failure Input. Remove connector J5 on UEM, marked ECA on the side of the UEM board. Measurevoltage between pins J5-3 and J5-4. Voltage should measure 5.0 (+ 0.25) VDC.



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Step 5: Testing Return Humidity Sensor Input. Remove wires (if installed) from terminals J7 (-) and J8 (+) on UEM, markedRH on the side of the UEM board. Measure voltage at terminals J7 (-) and J8 (+). Voltage should measure approximately 20VDC.


Step 6: Testing Outdoor Humidity Sensor Input. Remove wires (if installed) from terminals J9 (-) and J10 (+) on UEM, markedOH on the side of the UEM board. Measure voltage between terminals J9 (-) and J10 (+). Voltage should measureapproximately 20 VDC.



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Step 7: Testing Exhaust Fan Contactor Output. Remove connector (if installed) from J6 on UEM, marked XFC on the side ofthe UEM board. Turn minimum position potentiometer fully counter clock wise. Measure DC voltage between J6-1 and J6-2,should be 0 VDC. Turn minimum position potentiometer fully clock wise, after approximately 25 seconds, voltage shouldmeasure approximately 30 VDC.

If after completing tests 1 through 4, if any of the voltages specified in Test 4 were not present or were out of range, the UEMhas failed. Replace UEM.


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28.5. Test 5: Testing the SensorsStep 1: Test UCP Outdoor Air Sensor Input. The voltages listed below are measured with power applied to the unit and theOutdoor Air Sensor (OAS) wired into the circuit. Voltages may be measured at the Unitary Control Processor (UCP), or at theconnectors nearest the sensor. The OAS is measured between UCP terminals J1-15 & J1-16.

The resistance values (OHMs) are measured with the sensor disconnected and isolated from the UCP. The resistance may bemeasured at the connectors nearest the sensor, or in the respective plug near the printed circuit board. The electrical valuesmeasured, directly correspond with an outdoor temperature, that is interpreted by the UCP.

ZTEMPOHMs Volts ZTEMP OHMs Volts ZTEMPOHMs Volts°F Rx1K DC +/-5% °F Rx1K DC +/-5% °F Rx1K DC +/-5%-40 346.1 4.648 -39 333.5 4.468 -38 321.5 4.629

-37 310.0 4.609 -36 298.9 4.609 -35 288.3 4.590

-34 278.1 4.570 -33 268.3 4.570 -32 258.9 4.551

-31 249.9 4.531 -30 241.1 4.531 -29 232.7 4.512

-28 224.6 4.492 -27 216.8 4.473 -26 209.4 4.453

-25 202.2 4.434 -24 195.2 4.434 -23 188.6 4.414

-22 182.3 4.395 -21 176.0 4.375 -20 170.1 4.355

-19 164.4 4.336 -18 158.9 4.316 -17 153.6 4.297

-16 148.5 4.277 -15 143.5 4.258 -14 138.8 4.219

-13 134.2 4.199 -12 129.8 4.180 -11 125.5 4.160

-10 121.4 4.141 -9 117.4 4.121 -8 113.6 4.082

-7 109.9 4.063 -6 106.4 4.043 -5 103.0 4.023

-4 99.66 3.984 -3 96.48 3.965 -2 93.40 3.945

-1 90.43 3.906 0 87.56 3.887 1 84.80 3.848

2 82.13 3.828 3 79.50 3.789 4 77.06 3.770

5 74.65 3.730 6 72.33 3.711 7 70.09 3.672

8 67.92 3.652 9 65.82 3.613 10 63.80 3.594

11 61.85 3.555 12 59.96 3.516 13 58.13 3.496

14 56.37 3.457 15 54.66 3.418 16 53.01 3.398

17 51.41 3.359 18 49.87 3.320 19 48.38 3.281


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ZTEMPOHMs Volts ZTEMP OHMs Volts ZTEMPOHMs Volts°F Rx1K DC +/-5% °F Rx1K DC +/-5% °F Rx1K DC +/-5%20 46.94 3.262 21 45.54 3.223 22 44.19 3.184

23 42.88 3.145 24 41.62 3.125 25 40.40 3.086

26 39.21 3.047 27 38.07 3.008 28 36.96 2.969

29 35.89 2.930 30 34.85 2.910 31 33.84 2.871

32 32.87 2.832 33 31.94 2.793 34 31.04 2.754

35 30.18 2.734 36 29.33 2.695 37 28.52 2.656

38 27.73 2.617 39 26.97 2.578 40 26.22 2.559

41 25.51 2.520 42 24.81 2.480 43 24.14 2.441

44 23.48 2.422 45 22.85 2.383 46 22.23 2.344

47 21.64 2.305 48 21.06 2.285 49 20.50 2.246

50 19.96 2.207 51 19.43 2.188 52 18.92 2.148

53 18.42 2.109 54 17.94 2.090 55 17.47 2.051

56 17.02 2.012 57 16.58 1.992 58 16.15 1.953

59 15.74 1.934 60 15.33 1.895 61 14.94 1.855

62 14.56 1.836 63 14.19 1.797 64 13.83 1.777

65 13.49 1.738 66 13.15 1.719 67 12.82 1.680

68 12.50 1.660 69 12.19 1.641 70 11.89 1.602

71 11.60 1.582 72 11.31 1.543 73 11.03 1.523

74 10.76 1.504 75 10.50 1.465 76 10.25 1.445

77 10.00 1.426 78 9.759 1.406 79 9.525 1.367

80 9.297 1.348 81 9.076 1.328 82 8.860 1.309

83 8.650 1.289 84 8.446 1.250 85 8.247 1.230

86 8.054 1.211 87 7.866 1.191 88 7.682 1.172

89 7.504 1.152 90 7.330 1.133 91 7.161 1.113

92 6.996 1.094 93 6.836 1.074 94 6.680 1.055

ZTEMPOHMs Volts ZTEMP OHMs Volts ZTEMPOHMs Volts°F Rx1K DC +/-5% °F Rx1K DC +/-5% °F Rx1K DC +/-5%


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95 6.528 1.035 96 6.380 1.016 97 6.235 0.996

98 6.095 0.977 99 5.958 0.957 100 5.824 0.938

101 5.694 0.918 102 5.567 0.898 103 5.444 0.898

104 5.323 0.879 105 5.206 0.859 106 5.091 0.840

107 4.980 0.820 108 4.871 0.801 109 4.765 0.801

110 4.662 0.781 111 4.561 0.762 112 4.462 0.762

113 4.366 0.742 114 4.273 0.723 115 4.181 0.703

116 4.092 0.703 117 4.005 0.684 118 3.921 0.664

119 3.838 0.664 120 3.757 0.645 121 3.678 0.645

122 3.601 0.625 123 3.526 0.605 124 3.453 0.605

125 3.381 0.586 126 3.312 0.586 127 3.244 0.566

128 3.177 0.566 129 3.112 0.547 130 3.049 0.547

131 2.987 0.527 132 2.926 0.527 133 2.867 0.508

134 2.809 0.508 135 2.753 0.488 136 2.698 0.488

137 2.644 0.469 138 2.591 0.469 139 2.540 0.449

140 2.489 0.449 141 2.440 0.449 142 2.392 0.430

143 2.345 0.430 144 2.300 0.410 145 2.255 0.410

146 2.211 0.410 147 2.168 0.391 148 2.126 0.391

149 2.085 0.371 150 2.045 0.371 151 2.006 0.371

152 1.968 0.352 153 1.930 0.352 154 1.894 0.352

155 1.858 0.332 156 1.823 0.332 157 1.789 0.332

158 1.755 0.332


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Step 2: Test Supply Air Sensor And Return Air Sensor Inputs. The voltages listed below are measured with power applied tothe unit and the Supply Air Sensor (SAS) or Return Air Sensor (RAS) wired into the circuit. Voltages may be measured at theUEM, or at the connectors nearest the respective sensor. SAS is measured between UEM terminals J2-1 & J2-2, RAS ismeasured between UEM terminals J3-1 & J3-2.

The resistance values (OHMs) are measured with the sensor disconnected and isolated from the UEM. The resistance may bemeasured at the connectors nearest the sensor, or in the respective plug near the printed circuit board. The electrical valuesmeasured, directly correspond with a supply or return air temperature, that is interpreted by the UCP.


33 31.94 3.516 34 31.04 3.496 35 30.18 3.457

36 29.33 3.418 37 28.52 3.398 38 27.73 3.359

39 26.97 3.340 40 26.22 3.301 41 25.51 3.281

42 24.81 3.242 43 24.14 3.203 44 23.48 3.184

45 22.85 3.145 46 22.23 3.105 47 21.64 3.086

48 21.06 3.047 49 20.50 3.027 50 19.96 2.988

51 19.43 2.949 52 18.92 2.930 53 18.42 2.891

54 17.94 2.852 55 17.47 2.832 56 17.02 2.793

57 16.58 2.754 58 16.15 2.734 59 15.74 2.695

60 15.33 2.656 61 14.94 2.637 62 14.56 2.598

63 14.19 2.559 64 13.83 2.539 65 13.49 2.500

66 13.15 2.480 67 12.82 2.441 68 12.50 2.402

69 12.19 2.383 70 11.89 2.344 71 11.60 2.324

72 11.31 2.285 73 11.03 2.246 74 10.76 2.227

75 10.50 2.188 76 10.25 2.168 77 10.00 2.129

78 9.759 2.109 79 9.525 2.070 80 9.297 2.051

81 9.076 2.012 82 8.860 1.992 83 8.650 1.953

84 8.446 1.934 85 8.247 1.895 86 8.054 1.875

87 7.866 1.855 88 7.682 1.816 89 7.504 1.797

90 7.330 1.758 91 7.161 1.738 92 6.996 1.719


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96 6.380 1.602 97 6.235 1.582 98 6.095 1.563

99 5.958 1.543 100 5.824 1.504 101 5.694 1.484

102 5.567 1.465 103 5.444 1.445 104 5.323 1.426

105 5.206 1.406 106 5.091 1.367 107 4.980 1.348

108 4.871 1.328 109 4.765 1.309 110 4.662 1.289

111 4.561 1.270 112 4.462 1.250 113 4.366 1.230

114 4.273 1.211 115 4.181 1.191 116 4.092 1.172

117 4.005 1.152 118 3.921 1.133 119 3.838 1.113

120 3.757 1.094 121 3.678 1.074 122 3.601 1.055

123 3.526 1.035 124 3.453 1.016 125 3.381 1.016

126 3.312 0.996 127 3.244 0.977 128 3.177 0.957

129 3.112 0.938 130 3.049 0.918 131 2.987 0.918

132 2.926 0.898 133 2.867 0.879 134 2.809 0.859

135 2.753 0.859 136 2.698 0.840 137 2.644 0.820

138 2.591 0.820 139 2.540 0.801 140 2.489 0.781

141 2.440 0.762 142 2.392 0.762 143 2.345 0.742

144 2.300 0.742 145 2.255 0.723 146 2.211 0.703

147 2.168 0.703 148 2.126 0.684 149 2.085 0.684

150 2.045 0.664 151 2.006 0.645 152 1.968 0.645

153 1.930 0.625 154 1.894 0.625 155 1.858 0.605

156 1.823 0.605 157 1.789 0.586 158 1.755 0.586

159 1.722 0.566 160 1.690 0.566 161 1.659 0.547

162 1.628 0.547 163 1.598 0.527 164 1.568 0.527

165 1.539 0.508 166 1.511 0.508 167 1.484 0.508

168 1.457 0.488 169 1.430 0.488 170 1.404 0.469


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Step 3: Testing The Return Humidity Sensor (RHS). Locate terminals J7 (-) and J8 (+) on the UEM, marked RH on the side ofthe UEM board. Leave the sensor (if installed) connected to the UEM, and measure the operating current. The normal range foroperating current is 4 to 20 mA (milliamps). Replace sensor if not within range (+/- 10 %).

Note: The RHS is polarity sensitive, verify polarity is correct before condemning the sensor. Reversing polarity will notdamage any of the controls, but the RHS will not work if the polarity is reversed.

Step 4: Testing The Outdoor Humidity Sensor (OHS). Locate terminals J9 (-) and J10 (+) on the UEM, marked OH on the sideof the UEM board. Leave the sensor (if installed) connected to the UEM, and measure the operating current. The normal rangefor operating current is 4 to 20 mA (milliamps). Replace sensor if not within range (+ 10 %).

Note: The OHS is polarity sensitive, verify polarity is correct before condemning the sensor. Reversing polarity will notdamage any of the controls, but the OHS will not work if the polarity is reversed.

29. Testing The Defrost Module (10-20 Ton Heat Pumps only)This series of tests can be conducted in any mode, as long as the UCP is powered up. Test 1 simulates an open DefrostTermination Switch (DT), and verifies the integrity of the time interval switching circuit input. Test 2 simulates a closed DT,


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and also verifies the integrity of the time interval switching circuit input. Test 3 verifies the integrity of the Switch Over Valve(SOV) relay circuit.

29.1. Test 1: Simulates an open Defrost Termination Switch (DT)Remove the (RED) wire from terminal number J6 on the DFM, to simulate an open DT condition. Measure the DC voltagebetween pin J2-3 and LTB-20 (Note: On equipment manufactured before 06/93 substitute LTB-16 for LTB-20), with theswitches (SW1 and SW2) set in the positions below.

SW1 SW2 DT Expected DC Volts DC Volts Measured OFF OFF OPEN 0.56 (+/- 5 %)

ON OFF OPEN 0.54 (+/- 5 %)

OFF ON OPEN 0.52 (+/- 5 %)

ON ON OPEN 0.41 (+/- 5 %)

29.2. Test 2: Simulates a closed Defrost Termination Switch (DT) Reconnect the (RED) wire to terminal number J6 on the DFM. Install a jumper from terminal J6 to LTB-17 (Note: Onequipment manufactured before 06/93 substitute LTB-18 for LTB-17), to simulate a closed DT condition. Measure the DCvoltage between pin J2-3 and LTB-20 (Note: On equipment manufactured before 06/93 substitute LTB-16 for LTB-20), withthe switches (SW1 and SW2) set in the positions below.

SW1 SW2 DT Expected DC Volts DC Volts MeasuredOFF OFF CLOSED 3.34 (+/- 5 %)

ON OFF CLOSED 2.88 (+/- 5 %)

OFF ON CLOSED 2.39 (+/- 5 %)

ON ON CLOSED 1.08 (+/- 5 %)


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29.3. Test 3: Testing The SOV Relay CircuitStep 1: Place the unit in the Cooling or Defrost mode, so that the SOVs should be energized. Test for 24 VAC, with wires inplace, between DFM terminals J3 and J4. If 24 VAC is not present, contacts should be closed, and SOVs should be energized.If SOVs are not energized test TNS3 transformer, a transformer failure may have occurred. If 24 VAC is present, K1 contactsare not closed, and SOVs will not be energized. Proceed to Step 2.

Step 2: Test for K1 relay coil voltage, remove J1 on DFM. Test the J1 connector terminals for nominal 28 VDC. If voltage ispresent and K1 contacts were not closed in Step 1, DFM is defective, replace DFM. If 28 VDC is not present proceed to Step 3.


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Step 3: If 28 VDC was not present in Step 2, open unit disconnect switch. Locate J1 on the UCP. Connect positive meter leadto terminal J1-14, wire number 83A (BLACK). Connect negative meter lead to LTB- 20 (Note: On equipment manufacturedbefore 06/93 substitute LTB-16 for LTB-20) screw terminal. Close the unit disconnect switch, and place the unit in the Coolingor Defrost mode so that the SOVs should be energized. Measure DC voltage between LTB-20 (Note: On equipmentmanufactured before 06/93 substitute LTB-16 for LTB-20) and J1-14. If 28 VDC is present, a wiring or terminal problemexists. If 28 VDC is not present, the UCP is defective, replace UCP.


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30. Testing The Coil Temperature Sensor (CTS)The voltages listed below are measured with power applied to the unit and the Coil Temperature Sensor (CTS) wired into thecircuit. Voltages may be measured at the Unitary Control Processor (UCP), the CTS is measured at the Unitary EconomizerModule (UEM) if an economizer is present, or at the connectors nearest the sensor. CTS is measured between UCP terminalsJ2-15 & J2-17, or UEM terminals J4-2 & J4-3 if an economizer is present.

The resistance values (OHMs) are measured with the sensor disconnected and isolated from the UCP. The resistance may bemeasured at the connectors nearest the sensor, or in the respective plug near the printed circuit board. The electrical valuesmeasured, directly correspond with a coil temperature, that is interpreted by the UCP.

ZTEMPOHMs Volts ZTEMP OHMs Volts ZTEMPOHMs Volts°F Rx1K DC +/-5% °F Rx1K DC +/-5% °F Rx1K DC +/-5%-40 346.1 4.648 -39 333.5 4.468 -38 321.5 4.629

-37 310.0 4.609 -36 298.9 4.609 -35 288.3 4.590

-34 278.1 4.570 -33 268.3 4.570 -32 258.9 4.551

-31 249.9 4.531 -30 241.1 4.531 -29 232.7 4.512

-28 224.6 4.492 -27 216.8 4.473 -26 209.4 4.453

-25 202.2 4.434 -24 195.2 4.434 -23 188.6 4.414

-22 182.3 4.395 -21 176.0 4.375 -20 170.1 4.355

-19 164.4 4.336 -18 158.9 4.316 -17 153.6 4.297

-16 148.5 4.277 -15 143.5 4.258 -14 138.8 4.219

-13 134.2 4.199 -12 129.8 4.180 -11 125.5 4.160

-10 121.4 4.141 -9 117.4 4.121 -8 113.6 4.082

-7 109.9 4.063 -6 106.4 4.043 -5 103.0 4.023

-4 99.66 3.984 -3 96.48 3.965 -2 93.40 3.945

-1 90.43 3.906 0 87.56 3.887 1 84.80 3.848

2 82.13 3.828 3 79.50 3.789 4 77.06 3.770

5 74.65 3.730 6 72.33 3.711 7 70.09 3.672

8 67.92 3.652 9 65.82 3.613 10 63.80 3.594

11 61.85 3.555 12 59.96 3.516 13 58.13 3.496

14 56.37 3.457 15 54.66 3.418 16 53.01 3.398

17 51.41 3.359 18 49.87 3.320 19 48.38 3.281

ZTEMPOHMs Volts ZTEMP OHMs Volts ZTEMPOHMs Volts


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°F Rx1K DC +/-5% °F Rx1K DC +/-5% °F Rx1K DC +/-5%20 46.94 3.262 21 45.54 3.223 22 44.19 3.184

23 42.88 3.145 24 41.62 3.125 25 40.40 3.086

26 39.21 3.047 27 38.07 3.008 28 36.96 2.969

29 35.89 2.930 30 34.85 2.910 31 33.84 2.871

32 32.87 2.832 33 31.94 2.793 34 31.04 2.754

35 30.18 2.734 36 29.33 2.695 37 28.52 2.656

38 27.73 2.617 39 26.97 2.578 40 26.22 2.559

41 25.51 2.520 42 24.81 2.480 43 24.14 2.441

44 23.48 2.422 45 22.85 2.383 46 22.23 2.344

47 21.64 2.305 48 21.06 2.285 49 20.50 2.246

50 19.96 2.207 51 19.43 2.188 52 18.92 2.148

53 18.42 2.109 54 17.94 2.090 55 17.47 2.051

56 17.02 2.012 57 16.58 1.992 58 16.15 1.953

59 15.74 1.934 60 15.33 1.895 61 14.94 1.855

62 14.56 1.836 63 14.19 1.797 64 13.83 1.777

65 13.49 1.738 66 13.15 1.719 67 12.82 1.680

68 12.50 1.660 69 12.19 1.641 70 11.89 1.602

71 11.60 1.582 72 11.31 1.543 73 11.03 1.523

74 10.76 1.504 75 10.50 1.465 76 10.25 1.445

77 10.00 1.426 78 9.759 1.406 79 9.525 1.367

80 9.297 1.348 81 9.076 1.328 82 8.860 1.309

83 8.650 1.289 84 8.446 1.250 85 8.247 1.230

86 8.054 1.211 87 7.866 1.191 88 7.682 1.172

89 7.504 1.152 90 7.330 1.133 91 7.161 1.113

92 6.996 1.094 93 6.836 1.074 94 6.680 1.055



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98 6.095 0.977 99 5.958 0.957 100 5.824 0.938

101 5.694 0.918 102 5.567 0.898 103 5.444 0.898

104 5.323 0.879 105 5.206 0.859 106 5.091 0.840

107 4.980 0.820 108 4.871 0.801 109 4.765 0.801

110 4.662 0.781 111 4.561 0.762 112 4.462 0.762

113 4.366 0.742 114 4.273 0.723 115 4.181 0.703

116 4.092 0.703 117 4.005 0.684 118 3.921 0.664

119 3.838 0.664 120 3.757 0.645 121 3.678 0.645

122 3.601 0.625 123 3.526 0.605 124 3.453 0.605

125 3.381 0.586 126 3.312 0.586 127 3.244 0.566

128 3.177 0.566 129 3.112 0.547 130 3.049 0.547

131 2.987 0.527 132 2.926 0.527 133 2.867 0.508

134 2.809 0.508 135 2.753 0.488 136 2.698 0.488

137 2.644 0.469 138 2.591 0.469 139 2.540 0.449

140 2.489 0.449 141 2.440 0.449 142 2.392 0.430

143 2.345 0.430 144 2.300 0.410 145 2.255 0.410

146 2.211 0.410 147 2.168 0.391 148 2.126 0.391

149 2.085 0.371 150 2.045 0.371 151 2.006 0.371

152 1.968 0.352 153 1.930 0.352 154 1.894 0.352

155 1.858 0.332 156 1.823 0.332 157 1.789 0.332

158 1.755 0.332


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31. Testing The CTI (3-50 Ton CV only)This series of tests will allow you to test the CTI, and verify the output to the UCP. Test 1 will verify the Mode output. Test 2 will verify the Cooling Set point output. Test 3 will verify the Heating Set point output. Test 4 will verify the ZoneTemperature output. Conduct the tests in numerical order until the problem is found.

Important: The 27.5-50 Ton VAV units can not be operated with a CTI.

Note: Kill system power at the service disconnect, before setting up the unit. Reapply power to the unit for testing.

31.1. Test 1: Testing The Mode OutputStep 1: After checking the Room Thermostat, kill the unit power at the service disconnect, and remove the thermostat wires atthe unit LTB.Step 2: Locate connector J7 on the UCP. Install meter leads between connector terminals J7-2 and J7-10. Reapply power, thenmeasure the DC voltage. The DC voltage measured should flash approximately every 0.5 seconds. The voltage level shouldmeasure less than 0.8 VDC at the low end of the cycle, and greater than 2.5 VDC at the high end of the cycle. If voltage doesnot flash, CTI has failed, replace CTI.


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31.2. Test 2: Testing The Cooling Set Point Output

Step 1: Kill the unit power at the service disconnect.Step 2: Locate connector J7 on the UCP. Install meter leads between connector terminals J7-2 and J7-8. Reapply power, andjumper LTB terminals as shown below to measure DC voltages. Note: If measured voltage is out of range, replace the CTI

Terminals Jumpered Expected DC Volts DC Volts MeasuredNONE 5.00 (+/- 5 %)

LTB-14 to LTB-1 3.71 (+/- 5 %)

LTB-14 to LTB-4 3.14 (+/- 5 %)

LTB-14 to LTB-1 & 4 2.58 (+/- 5 %)Note: On equipment manufactured before 06/93 substitute LTB-15 for LTB-14.


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31.3. Test 3: Testing The Heating Set Point Output

Step 1: Kill the unit power at the service disconnect.Step 2: Locate connector J7 on the UCP. Install meter leads between connector terminals J7-2 and J7--9. Reapply power, andjumper LTB terminals as shown below and measure DC voltages. If measured voltage is out of range, replace the CTI.


LTB-14 to LTB-5 2.80 (+/- 5 %)

LTB-14 to LTB-3 3.71 (+/- 5 %)

LTB-14 to LTB-9 3.14 (+/- 5 %)

LTB-14 to LTB-5,3 & 9 1.84 (+/- 5 %)

Note: On equipment manufactured before 06/93 substitute LTB-15 for LTB-14.


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31.4. Test 4: Testing The Zone Temperature OutputStep 1: Kill the unit power at the service disconnect.Step 2: Locate connector J7 on the UCP. Install meter leads between connector terminals J7-2 and J7- 11. Reapply power, andjumper LTB terminals as shown below and measure DC voltages. If measured voltage is out of range, replace the CTI.


LTB-14 to LTB-7 3.71 (+/- 5 %)

LTB-14 to LTB-8 3.14 (+/- 5 %)

LTB-14 to LTB-7 & 8 2.58 (+/- 5 %)

Note: On equipment manufactured before 06/93 substitute LTB-15 for LTB-14.


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32. Testing the Exhaust Fan Set Point Panel (27.5-50 Ton)

Step 1: Disconnect the two wires connected to terminals J1 and J2 on the Exhaust Fan Set Point Panel (EFSP) and remove theSet Point Panel from the unit.

Step 2: Set the EFSP potentiometer on the panel to 50%.

Step 3: Measure the resistance between the two terminals J1 and J2.

Exhaust Fan Setpoint

Nominal NominalSetpoint Resistance Voltage

(%) (Ohms) (V DC)

0 889 4.085 851 4.0510 812 4.0115 773 3.9720 734 3.9325 695 3.8830 656 3.8335 617 3.7840 578 3.7145 539 3.6550 500 3.5755 461 3.4960 422 3.3965 383 3.2870 344 3.1675 305 3.0280 266 2.8585 227 2.6690 188 2.4295 150 2.14

100 111 1.78


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33. Unit Variable Air Volume Module (UVM) Test Procedures (27.5-50 Ton)

33.1. Test 1: Testing Inlet Guide Vane/Variable Frequency Drive (IGV/VFD) Output

Step 1: Using the Test Mode, step the unit to the first test. Verify that 8.5 VDC is present between terminals J5-8 and J5-5 forIGV’s or 10VDC for VFD’s. If voltages are reversed, switch SW1 on the UCP to the opposite position and recycle power..

Step 2: If the voltage is not present or is incorrect, verify wires 160A and 160B are connected properly. Measure the voltage atJ1-11 to ground. It should be a pulsating between 5 VDC.

Step 3: If the voltage to the IGV/VFD is still not present, verify that the remaining wires are properly connected between theUCP and the UVM. If Step 2 and Step 3 checkout and the voltage is still not present at the IGV/VFD output, replace the UVM.

33.2. Test 2: Testing the Static Pressure Transducer Input

Step 1: With main power to the unit turned "Off", disconnect all of the tubing to the Static Pressure Transducer (STP).

Step 2: With the system MODE "Off", apply power to the unit and measure the voltage between J10 and J8 on the UVM. Thevoltage should be approximately 5 VDC. If not, check the wiring between the UCP and the UVM. If the wiring checks, replaceUVM.

Step 3: Measure the voltage between J9 and J8 on the UVM. The voltage should be approximately 0.25 VDC. If not, check thewiring between the UVM and the SPT. If the wiring checks replace the SPT.

Step 4: Apply 2.0" w.c. pressure to the HI port on the SPT. Measure the voltage between J8 and J9. The voltage should be 1.75(± .14) VDC. If not, replace the SPT.

Note: The SPT is susceptible to interference from VFD’s. Make sure the SPT is mounted on plastic standoffs and is nottouching any sheet metal.

33.3. Test 3: Testing the Temperature Sensor Input

Step 1: With power applied to system, turn the ZSM MODE switch "Off".

Step 2: Testing the zone temperature sensor input. Disconnect the P23 connector from the UVM. Measure the voltage betweenthe J3-1 terminal and ground. The voltage should measure approximately 5 VDC. Now, measure the resistance betweenterminal P23-1 and ground. Measure the temperature at the zone sensor location. Verify the accuracy of the SAS. Replace thesensor if it is out of range.

Step 3: Testing the outdoor air sensor Input. Disconnect the P22 connector from the UVM. Measure the voltage betweenterminals J2-1 and J2-2. The voltage should measure approximately 5 VDC. Now, measure the resistance between the two P22terminals. Measure the temperature at the OAS location. Verify the accuracy of the OAS. Replace the sensor if it is out ofrange.


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33.4. Test 4: Testing the VAV Set Point Input

Step 1: With power applied to the system, turn the ZSM MODE switch to "Off".

Step 2: Reset Amount Input. Disconnect the wire connected to the J7 terminal on the UVM. Measure the voltage between theJ7 and J8 terminal. The voltage should measure approximately 5 VDC.

Step 3: Static Pressure Deadband. Disconnect the P25 connector on the UVM. Measure the voltage between the J5-3 and J5-4terminal. The voltage should measure approximately 5 VDC.

Step 4: Static Pressure Set Point. Disconnect the wires connected to J11 and J12 on the UVM. Measure the voltage betweenthe J11 and J12 terminal. The voltage should measure approximately 5 VDC.

Step 5: Morning Warm up Set Point. Disconnect the P24 connector from the UVM. Measure the voltage between the J4-1 andJ4-2 terminal. The voltage should measure approximately 5 VDC.

Step 6: Reset Set Point. Disconnect the P7 connector from the UCP. Measure the voltage between the J7-9 terminal andGround. The voltage should measure approximately 5 VDC.

33.5. Test 5: Testing the Inlet Guide Vane Actuator (IGVA)

Step 1: Using the Test Mode procedure, measure the voltage between the (+) and (-) terminals on the actuator. The voltageshould be 8.5 VDC. If not, check the wiring between the UVM and the IGV actuator. If the wiring checks, return to Test 1.

Step 2: If the voltage above is present and the actuator is not opening, verify that 24 VAC is present between terminals T1 andT2. If the voltage is present, replace actuator.

Note: The IGVA can manually be driven open by shorting the (F) terminal to either the (+) or (-) terminals. The IGVA willdrive closed when the short is removed.

33.6. Test 6: Testing the VFD

Step 1: Verify that the keypad in control box is powered. If not, check the power wires to the VFD and the Keypad cable.

Step 2: Using the Test Mode, verify that the fan starts and the speed increases until the SA Pressure reaches the "Set Point" onVAV Set Point panel. If the fan does not start, check for "Fault Conditions" on the VFD Keypad.

Step 3: If no "Fault Conditions" exist and the fan started but did not ramp up to speed, verify the "speed reference voltage"output from the UVM between terminals J5-8 and J5-5.

Step 4: If no "Fault Conditions" exist and the fan did not start, verify that the Fan relay is energized and the VFD "StartCommand" is properly wired from the Fan relay, (24 volts on the Logic Input 2 (LI2) terminal). Verify that the jumper between+24V and the LI1 terminal is properly connected.

Step 5: Verify that 115 VAC is present from the transformer on the VFD assembly panel.


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33.7. Test 7: Testing the VAV Set Point Panel

Step 1: Disconnect the wiring from the VAV Set Point Panel and Remove it from the unit.

Step 2: Supply Air Cooling Set Point. Measure the resistance between pins 1 and 2. The resistance range across the terminalsis approximately 200 to 1200 ohms. At the 60° F Set Point setting, the resistance should be 695 (± 39) ohms.

Step 3: Morning Warm Up Set Point. Measure the resistance between pins 3 and 4. The resistance range across the terminalsis approximately 000 to 1000 ohms. At the 70° F Set Point setting, the resistance should be 500 (± 39) ohms.

Step 4: Reset Set Point. Measure the resistance between pins 7 and 8. The resistance range across the terminals isapproximately 000 to 1000 ohms. At the 70° F Set Point setting, the resistance should be 500 (± 39) ohms.

Step 5: Reset Amount. Measure the resistance between pins 5 and 6. a. The resistance range across the terminals isapproximately 50 to 750 ohms. At the 10° F Set Point setting, the resistance should be 500 (± 39) ohms.

Step 6: Static Pressure Set Point. Measure the resistance between pins 11 and 12. The resistance range across the terminals isapproximately 80 to 780 ohms. At the 1.3" w.c. Set Point setting, the resistance should be 490 (± 28) ohms.

Step 7: Static Pressure Deadband. Measure the resistance between pins 9 and 10. The resistance range across the terminals isapproximately 000 to 1000 ohms. At the 0.5" w.c. Set Point setting, the resistance should be 500 (± 39) ohms.

Front of VAV Panel Back of VAV Panel


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Supply Air Cooling Setpoint Morning Warmup Setpoint

Nominal Nominal Nominal NominalSetpoint Resistance Voltage Setpoint Resistance Voltage(Deg F) (Ohms) (V DC) (Deg F) (Ohms) (V DC)

40 1084 2.60 50 889 2.3541 1065 2.58 51 870 2.3342 1045 2.56 52 850 2.3043 1026 2.53 53 831 2.2744 1006 2.51 54 812 2.2445 987 2.48 55 792 2.2146 967 2.46 56 773 2.1847 948 2.43 57 753 2.1548 928 2.41 58 734 2.1249 909 2.38 59 714 2.0850 889 2.35 60 695 2.0551 870 2.33 61 675 2.0252 850 2.30 62 656 1.9853 831 2.27 63 636 1.9454 812 2.24 64 617 1.9155 792 2.21 65 597 1.8756 773 2.18 66 578 1.8357 753 2.15 67 558 1.7958 734 2.12 68 539 1.7559 714 2.08 69 519 1.7160 695 2.05 70 500 1.6761 675 2.02 71 481 1.6262 656 1.98 72 461 1.5863 636 1.94 73 442 1.5364 617 1.91 74 422 1.4865 597 1.87 75 403 1.4466 578 1.83 76 383 1.3967 558 1.79 77 364 1.3368 539 1.75 78 344 1.2869 519 1.71 79 325 1.2370 500 1.67 80 305 1.1771 481 1.62 81 286 1.1172 461 1.58 82 266 1.0573 442 1.53 83 247 0.9974 422 1.48 84 227 0.9375 403 1.44 85 208 0.8676 383 1.39 86 188 0.7977 364 1.33 87 169 0.7278 344 1.28 88 150 0.6579 325 1.23 89 130 0.5880 305 1.17 90 111 0.50


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Reset Setpoint Reset Amount

Return/Zone Outdoor Nominal Nominal Nominal NominalSetpoint Setpoint Resistance Voltage Setpoint Resistance Voltage(Deg F) (Deg F) (Ohms) (V DC) (Deg F) (Ohms) (V DC)

50 0 889 2.35 0 684 2.0351 2.5 870 2.33 1 662 1.9952 5 850 2.30 2 641 1.9553 7.5 831 2.27 3 631 1.9354 10 812 2.24 4 610 1.8955 12.5 792 2.21 5 590 1.8656 15 773 2.18 6 571 1.8257 17.5 753 2.15 7 552 1.7858 20 734 2.12 8 533 1.7459 22.5 714 2.08 9 515 1.7060 25 695 2.05 10 488 1.6461 27.5 675 2.02 11 471 1.6062 30 656 1.98 12 455 1.5663 32.5 636 1.94 13 438 1.5264 35 617 1.91 14 414 1.4665 37.5 597 1.87 15 399 1.4366 40 578 1.83 16 376 1.3767 42.5 558 1.79 17 362 1.3368 45 539 1.75 18 340 1.2769 47.5 519 1.71 19 320 1.2170 50 500 1.67 20 299 1.1571 52.5 481 1.62 72 55 461 1.58 73 57.5 442 1.53 74 60 422 1.48 75 62.5 403 1.44 76 65 383 1.39 77 67.5 364 1.33 78 70 344 1.28 79 72.5 325 1.23 80 75 305 1.17 81 77.5 286 1.11 82 80 266 1.05 83 82.5 247 0.99 84 85 227 0.93 85 87.5 208 0.86 86 90 188 0.79 87 92.5 169 0.72 88 95 150 0.65 89 97.5 130 0.58 90 100 111 0.50


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Static Pressure Setpoint (I.W.C.) Static Pressure Deadband (I.W.C.)

Nominal Nominal Nominal NominalSetpoint Resistance Voltage Setpoint Resistance Voltage(I.W.C.) (Ohms) (V DC) (I.W.C.) (Ohms) (V DC)

0 743 2.13 0.2 753 2.150.1 724 2.10 0.25 707 2.070.2 704 2.07 0.3 662 1.990.3 685 2.03 0.35 620 1.910.4 665 2.00 0.4 590 1.860.5 646 1.96 0.45 542 1.760.6 626 1.93 0.5 506 1.680.7 607 1.89 0.55 463 1.580.8 587 1.85 0.6 430 1.500.9 568 1.81 0.65 384 1.391 548 1.77 0.7 347 1.29

1.1 529 1.73 0.75 306 1.171.2 509 1.69 0.8 274 1.071.3 490 1.64 0.85 225 0.921.4 470 1.60 0.9 180 0.761.5 451 1.55 0.95 138 0.611.6 431 1.51 1 103 0.471.7 412 1.461.8 393 1.411.9 373 1.362 354 1.31

2.1 334 1.252.2 315 1.202.3 295 1.142.4 276 1.082.5 256 1.02


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34. Testing The UCP / TCI InterfaceThis Test will allow you to determine whether a communication problem is a result of a failed UCP, or if an ICS Device /Communication Link problem exists. Complete the Test Steps in numerical order, to locate the source of the problem.

34.1. Test 1: Testing The UCP Output To The TCINote: Prior to performing Test 1, Steps 1-6, verify that the cable which connects the UCP to the TCI is installed properly. Wirenumber 43A of the TCI cable should be on the far right hand side, closest to the dip switches, on the TCI connector junction J1.If it is not, disconnect both ends of the cable, and reinstall the cable connectors in reverse.

Step 1: Remove plug connector J1 on the TCI. Measure AC voltage at disconnected plug between terminals J1-7, and J1-1.Voltage measured should be approximately 24 VAC. If 24 VAC is not present, test for voltage directly at UCP. Measurevoltage at connector junction J6, between terminals J6-1 and J6-7. If 24 VAC is present, replace TCI cable. If 24 VAC is notpresent, replace UCP.

Step 2: With plug connector J1 removed from the TCI. Measure DC voltage at disconnected plug between terminals J1-6, andJ1-1. Voltage measured should be approximately 30 VDC. If 30 VDC is not present, test for voltage directly at UCP. Measurevoltage at connector junction J6, between terminals J6-2 and J6-7. If 30 VDC is present, replace TCI cable. If 30 VDC is notpresent, replace UCP.


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Step 3: With plug connector J1 removed from the TCI. Measure DC voltage at disconnected plug between terminals J1-5, andJ1-1. Voltage measured should be approximately 4.67 VDC, +/- 0.25 VDC. If 4.67 (+/- 0.25) VDC is not present, test forvoltage directly at UCP. Measure voltage at connector junction J6, between terminals J6-3 and J6-7. If 4.67 (+/- 0.25) VDC ispresent, replace TCI cable. If 4.67 (+/- 0.25) VDC is not present, replace UCP.

Step 4: With plug connector J1 removed from the TCI. Measure DC voltage at disconnected plug between terminals J1-4, andJ1-1. Voltage measured should be approximately 5.0 VDC, +/- 0.25 VDC. If 5.0 (+/- 0.25) VDC is not present, test for voltagedirectly at UCP. measure voltage at connector junction J6, between terminals J6-4 and J6-7. If 5.0 (+/- 0.25) VDC is present,replace TCI cable. If 5.0 (+/- 0.25) VDC is not present, replace UCP

.

Step 5: With plug connector J1 removed from the TCI. Measure DC voltage at disconnected plug between terminals J1-3, andJ1-1. Voltage measured should be approximately 0 VDC, +/- 0.50 VDC. If 0 (+/- 0.50) VDC is not present, test for voltage


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directly at UCP. Measure voltage at connector junction J6, between terminals J6-5 and J6-7. If 0.0 (+/- 0.50) VDC is present,replace TCI cable. If 0.0 (+/- 0.50) VDC is not present, replace UCP.

Step 6: With plug connector J1 removed from the TCI. Measure DC voltage at disconnected plug between terminals J1-2, andJ1-1. Voltage measured should be approximately 30 VDC. If 30 VDC is not present, test for voltage directly at UCP. Measurevoltage at connector junction J6, between terminals J6-6 and J6-7. If 30 VDC is present, replace TCI cable. If 30 VDC is notpresent, replace UCP. If after completing Test 1, Steps 1 through 6, and no problems are found, an ICS Device /Communication Link problem exists.


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Section 5

35. Erratic Unit Operation (3-25 ton)

35.1. Economizer wiring harness has conductor(s) shorted to ground:There is a short piece of edge protector, which ships with the economizer / motorized outside air damper accessory. The pieceof edge protector is included in the plastic “bag of parts” which comes with the accessory. It is intended that the piece of edgeprotector be installed on any raw metal edge that the accessory wiring harness must be routed over.

Failure to install the edge protector, can result in the raw metal edge slicing through the wiring harness, causing problems withequipment operation and the Test mode both. The problem may surface immediately, or it may become evident over time withequipment operational vibration.

Remove power from the equipment and inspect the accessory wiring harness where it passes over the metal, look for damage tothe insulation on the conductors, repair conductors and protect them from further damage by isolating them from the metal.

35.2. Equipment wiring harness damaged in factory installation:When the equipment wiring harness is installed in the unit, a portion of the wiring harness must be routed from the control boxinto the evaporator blower section. This section of the wiring harness is for the indoor fan motor, and economizer / motorizedoutside air accessory.

The wiring harness must pass through two bulkhead, or block off panels, before reaching the evaporator blower section. If theinsulation on the conductors was damaged as the harness was installed, it may result in a conductor shorting to ground, causingproblems with equipment operation and the Test mode both. The problem may surface immediately, or it may become evidentover time with equipment operational vibration.

Remove power from the equipment and inspect the equipment wiring harness where it passes through each metal block off.Look for damage to the insulation on the conductors, repair conductors and protect them from further damage by isolating themfrom the metal.

35.3. A terminal backed out of the 15 pin polarized plug:When the economizer / motorized outside air 15 pin male plug end, is connected to the equipment 15 pin female plug end, aterminal may back out of one of the plugs if it were not locked securely into the plug housing. If the polarized plug ends are notcompletely connected together, so that the locking mechanisms are properly engaged, the same symptoms may be exhibited.Another symptom that could be associated with this, is a complaint that the equipment arbitrarily enters the Test mode, withoutmaking physical contact with the equipment.

Remove power from the equipment and inspect the polarized plug assembly carefully to determine if the plug ends are properlyengaged, or if a terminal has backed out of the plug housing. If either problem is noted, disconnect the plug ends and reseat theterminal in the plug making sure it locks into place (if necessary). Carefully re-connect the plug ends, ensuring they are properlyengaged, and re-apply power to the equipment.

35.4. J4 or J5 on the UCP not wired or plugged in properly (3-50 ton):If a problem exists in the J4 or J5 junction, located in the upper right hand corner of the Unitary Control Processor (UCP), allaround erratic operation may occur.

Remove power from the equipment, and inspect the two plugs to ensure that they are properly located and seated. Verify thatthe two plugs are wired correctly, by checking the wiring against the equipment connection diagram.

Note: If the Test mode is initiated directly on the Unitary Control Processor (UCP) at the J4 (TEST) pins, the indoor motor willnot operate when COOL 1 mode is entered, on dual circuit units.


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35.5. The polarized plugs are not configured properly on Heat Pump (3-20 ton):When an economizer, motorized outside air damper, or generic input/output module is installed, these plugs must be re-configured. If the polarized plugs (PPM8, PPF8, PPM9, and PPF10) in the unit control box are not configured properly, erraticoperation can occur.

On 3-7.5 Ton equipment manufactured after 06/93, when the Test mode is entered, the indoor fan motor will run for 15seconds, the fan motor will then turn “OFF”, and the equipment will not do anything else.

On equipment with “NO” economizer or motorized outside air damper, the plugs should be configured as illustrated below.

PPF10 PPF10

114A (Purple) 1 114A (Purple) 1115A (Blue) 2 113A (Black) 2

3 115A (Blue) 34

PPF8 PPM8 PPF8

107E (Yellow) 1 1 W26 (Purple) PPM8109E (Yellow) 2 2 W27 (Blue) 107E (Yellow ) 1 1 W26 (Purple)125A (Purple) 3 3 125B (Purple) 108E (Yellow) 2 2 W25 (Black)

109E (Yellow) 3 3 W27 (Blue) 125A (Purple) 4 4 125B (Purple)

PPM9 1 107C (Yellow) PPM9 2 109C (Yellow) 1 107C (Yellow) 3 2 108C (Yellow)

3 109C (Yellow) 4

3-7.5 Tons 10-20 Tons

On equipment with an economizer, motorized outside air damper or BAYDIAG001A, the plugs should be configured asillustrated below.

PPF10 PPF8 PPM8 PPM9

114A (Purple) 1 1 W26 (Purple) 107E (Yellow) 1 1 107C (Yellow)115A (Blue) 2 2 W27 (Blue) 108E (Yellow) 2 2 108C (Yellow)

3 3 125B (Purple) 109E (Yellow) 3 3 109C (Yellow) 125A (Purple) 4 4

PPF8 PPF10 PPM9 PPM8

107E (Yellow) 1 1 107C (Yellow) 114A (Purple) 1 1 W26 (Purple)109E (Yellow) 2 2 109C (Yellow) 113A (Black) 2 2 W25 (Black)125A (Purple) 3 3 115A (Blue) 3 3 W27 (Blue)

4 4 125B (Purple)

3-7.5 Tons 10-20 Tons


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36. The Equipment Fails To Energize Or De-Energize A Component

36.1. A UCP on board relay may have failed:The weakest link on a printed circuit board, under normal operating conditions, is the on board electromechanical devices(primarily relays). These are the “only” moving parts on a printed circuit board. If a particular device in a piece of equipmentwill not turn “ON” or “OFF”, some electrical measurements may be made to determine the source of the problem.

To determine the source of the problem, remove power from the equipment at the service disconnect, and utilize the systemschematic diagram to determine where to install meter leads.

For devices that are not de-energized: An “Ohm meter” should be installed across the on board relay contacts, to determine ifthey are opening when power is removed from the equipment. A short circuit indicates the contacts are welded.For devices that are not energized: An “AC volt meter” should be installed across the on board relay contacts, of the UnitaryControl Processor (UCP) for that device.

Re-apply power to the equipment, and operate the system in the suspect mode, to determine if the relay contacts are closing ornot. A voltage potential of 24V AC indicates the contacts are not closing, zero potential indicates they are closed.

36.2. Brass jumpers for compressor disable input are loose, corroded or missing:If the brass jumpers on the Low Voltage Terminal Board (LTB) are loose, corroded, or have been removed, the compressor(s)affected will not operate during normal operation, or in the Test mode.

Verify that the brass jumpers are intact, on equipment manufactured prior to 06/93 there should be two brass jumpers betweenterminals LTB-13, 15, and 17. On equipment manufactured after 06/93 there should be two brass jumpers between terminalsLTB-13, 14, and 15. If the brass jumpers are intact, verify that the terminals are tight, and that they are not corroded. A voltagemeasurement may be made to verify that 24V AC is being applied to the compressor disable inputs. This is accomplished bymeasuring from terminal J2-2 to ground (CPR1 DISABLE), and from terminal J2-3 to ground (CPR2 DISABLE).

Note: If the brass jumpers have been removed, and field installed wiring is connected to the LTB at those points, an externalfield mounted device may intentionally be keeping the compressor(s) from operating.

Obsolete LTB Current LTB

17 ⊕ ⊕ 15

15 ⊕ Jumpers Jumpers ⊕ 14

13 ⊕ ⊕ 13


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37. Will Not Work With A CTI (Constant Volume only)If the conventional thermostat interface (CTI) is disconnect, the low voltage terminal board (LTB) is jumpered, and the unit isoperating; there may be excessive leakage current from an electronic/programmable thermostat, because the thermostat does nothave dry contact closure relays. If enough leakage current passes through the thermostat being used, it can cause themicrocontrol Voyager to operate (heat, cool, fan on, etc.), when it is supposed to be “OFF”. The maximum allowable leakage,before it is in the gray area where it may be interpreted as an “ON” state (or call), is 4V AC. To test for leakage, turn thethermostat “OFF”, so that there is no active call for any operation. Using a voltmeter, measure the AC voltage from each circuit(Y1, Y2, W1, W2, G etc.) to ground, for proper operation there should not be more than 4V AC. If there is more than 4V ACpresent, in any circuit, an isolation relay should be installed as illustrated below.

Note: If you have a thermostat set where it is supposed to be cooling, and there is enough leakage current in the heat circuit, theVoyager will interpret the signals as a simultaneous call for heating and cooling. However, the microprocessor in the Voyageris programmed so that it will not allow simultaneous heating and cooling, the machine will sit idle and not operate at all.

Isolation RelayCommon terminal

� R � @ unit LTB n.o.

“G” terminal � � “G” terminal@ thermostat SPST Relay @ unit LTB

Isolation Relay Example With Leakage Current In "G" Circuit

38. No Communication Between ICS Device & Voyager

38.1. TCI-1 is being utilized:The Trane Communication Interface 1 (TCI-1) can be identified by the single red LED, located near the center of the printedcircuit board.

The TCI-1 is capable of “isolated” communication only, which means that it will only support communication between Voyagerand Tracer/Tracker/ComforTrac. The TCI-1 is not capable of supporting communication between a Voyager rooftop unit andComfort Manager. A Trane Communications Interface 2 or 3 (TCI-2 or 3) would have to be installed, in order to establishcommunication between the Voyager and Comfort Manager. A TCI-2 or 3 will have two LEDs (red and green), located on thebottom of the printed circuit board, between the two terminal blocks.

38.2. TCI-3 is being utilized, and Com Link board Non-isolated Comm:If a Trane Communication Interface 3 (TCI-3) is being utilized, and no communication is taking place, verify that the board hasbeen field converted for non-isolated communication.

If not in the non-isolated communication position, remove the four machine screws from the com link board, and then removethe com link board from the main printed circuit board. Rotate the com link board 90° counterclockwise, and re-install it, thecom select arrow on the main printed circuit board should be pointing at “NON-ISOLATED COM3 OR COM4”. For furtherinformation, reference publication EMTX-IN-16 / 22-6041-01.


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38.3. DIP switches on the TCI are set incorrectly:If the DIP switches on the Trane Communication Interface 2 or 3 (TCI-2 or 3) are set incorrectly, communications will not beestablished between Voyager and Comfort Manager.

There is only “one” correct setting for the DIP switches, switches 2 through 6 must all be “ON”. Switch number 1 must be inthe “OFF” position, unless the accessory duct high temperature sensor (or a smoke detector) is being used.

38.4. The comm link is connected to Comfort Manager incorrectly:There are two sets of communication link terminals on the Comfort Manager, one set for establishing communication betweenComfort Manager and an Integrated Comfort System (ICS) device (Tracer/Tracker/ComforTrac), and one set for establishingcommunication between Comfort Manager and the zone damper Unit Control Modules (UCMs).

The Voyager communicates with Comfort Manager on the UCM communication link. The Voyager must be connected toComfort Manager terminals TB2-1 & 2, marked “UCM”, or in a daisy chain with the zone damper UCMs. If the Voyager isconnected to Comfort Manager terminals TB2-2 & 3, marked “TR100”, it will not communicate. The communication link willhave to be relocated to the “UCM” terminals TB2-1 & 2, or connected in a daisy chain with the zone damper UCMs.

Note: A Voyager Zone Sensor Module (ZSM) can be installed directly on the Voyager, so that in the event of a communicationfailure between Voyager and Comfort Manager, the Voyager would continue to provide comfort for the zone.

38.5. No Communication Between Comfort Manager & VoyagerIf DIP switch number 1 on the TCI is set in the “ON” position, an accessory device must be installed across terminals TB2-1 &2, or the Voyager equipment will not operate.

If an accessory device (smoke detector contacts, duct high temperature sensor, etc.) is installed, and the circuit opens, theVoyager will completely shut down in less than one minute. A diagnostic will also be set and communicated to ComfortManager, the generated diagnostic will be displayed as “High temp” or “High temp input open”.

38.6. TCI-2 is being utilized:The TCI-2 can be identified by a single printed circuit board having two LEDs (red and green), located on the bottom of theprinted circuit board, between the two terminal blocks. The TCI-2 is capable of “non-isolated” communication only, whichmeans that it will only support communication between Voyager and Comfort Manager.

The TCI-2 is not capable of supporting communication between a Voyager rooftop unit and a Tracer/Tracker or ComforTrac.A TCI-1 or 3 must be installed, in order to establish communication between the Voyager and Tracer/Tracker or ComforTrac.

The TCI-1 can be identified by the single red LED, located near the center of the printed circuit board. The TCI-3 can beidentified by being a single printed circuit board, with a piggy back (satellite or daughter) com link board, and having twoLEDs (red and green), located on the bottom of the printed circuit board between the two terminal blocks.

38.7. TCI-3 is being utilized, and Com Link board Non-isolated comm:If a Trane Communication Interface 3 (TCI-3) is being utilized, and no communication is taking place, verify whether or not theboard has been field converted for non-isolated communication. If it has been, it will have to be converted back to supportisolated communication.

The com link board is attached to the main printed circuit board with four machine screws, remove these screws, and removethe com link board from the main printed circuit board. Rotate the com link board 90° clockwise, and re-install it, the comselect arrow on the main printed circuit board should be pointing at “ISOLATED COM3”. For further information, referencepublication EMTX-IN-16 / 22-6041-01.


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38.8. DIP switches on the TCI are set incorrectly:If the DIP switches on the Trane Communication Interface 1 or 3 (TCI-1 or 3) are set incorrectly, communications will not beestablished between Voyager and the Tracer/Tracker or ComforTrac.

There are several correct setting for the DIP switches, for both Tracer and Tracker/ComforTrac installations. To determine if avalid address is being utilized, remove power from the system at the equipment disconnect, and reference the respective deviceliterature or TCI Installation Guide (EMTX-IN-16 / 22-6041-01).

38.9. An ICS component failure may have occurred:After verifying that the correct Trane Communication Interface (TCI) has been installed, and a valid address is being utilizedfor the respective device, some other checks can be made to determine the source of the communication problem.

1. Start by removing power from the system, which is not communicating, and also from another nearby system, which iscommunicating, at their respective equipment disconnects.

2. Remove the TCI from both systems, and exchange them, making sure to exchange the addresses also (so that we can keepthe same “OLD” address with each respective unit). Restore power to both systems.

3. If both units communicate after this, then the first address setting on the non-communicating systems TCI was not working,the problem is solved.

4. If the problem followed the TCI, the TCI has failed and must be replaced.

5. If the non-communicating system will not communicate, and the communicating system continues to communicate, we willhave to do more testing. The problem could be in the com link, the Integrated Comfort System (ICS) device, or the UnitaryControl Processor (UCP).

6. Remove power from the two systems again at their respective equipment disconnects, and exchange the addresses of the twosystems (the communicating one and the non-communicating one). Restore power to both systems.

7. If the non-communicating system begins to communicate, and the communicating system will not communicate, then thenon-communicating address is a bad address in the ICS device. A new address, if available, will have to be selected. If a newaddress is not available, then the ICS device firmware or hardware will have to be replaced.

8. If the non-communicating system will not communicate, and the communicating system continues to communicate, we willhave to do more testing. The problem could be in the com link, or the UCP.

9. Remove power from the two systems again at their respective equipment disconnects, and exchange the UCP of the twosystems (the communicating one and the non-communicating one). Restore power to both systems.

10. If the non-communicating system begins to communicate, and the communicating system will not communicate, then theproblem followed the UCP. Replace the UCP.

11. If the non-communicating system will not communicate, and the communicating system continues to communicate, there isa problem in the com link.


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39. Sensors Fail And Return To Normal On An ICS Installation

39.1. Moisture on UEM has compromised integrity of conformal coating:Water on the economizer / motorized outside air damper printed circuit boards will cause problems. The problem is typicallytransparent in stand alone applications, but is often evident on Integrated Comfort System (ICS) jobs, due to recurring sensoralarms. Sensors may even appear when they do not exist. This problem can affect all Voyager products 8.5 through 25 Tons,with the economizer / motorized outside air damper accessory, with a “B” in the 7th digit of the unit model number (F20 serialdate code, May 1991, and later).

The failure of the Unitary Economizer Module (UEM), due to prolonged moisture contamination, may exhibit the followingsymptoms:1. Erroneous / Erratic Sensor Failure Alarms (ICS jobs)2. Erratic Economizer Damper Operation3. No Economizer Operation

The source of the moisture is primarily rain water, as the board is located under the access cover on the fresh air hood. If theaccess cover is not tightly sealed, rain can leak into the hood, and onto the printed circuit board. The printed circuit board has aconformal (protective) coating for moisture protection. However, water dripping on the board is too severe and if it continues,the described problem will likely occur.

The conformal (protective) coating on the printed circuit board has been upgraded, a flow coating process is now in production,instead of a double spot coating. The printed circuit board must be replaced, with part number MOD-0145 or later. To furtherresolve the problem, the access cover on the fresh air hood has been revised. The long slots on the sides have been removed,and additional fastening screws have been added. This will help hold the access cover tightly against the gasketing around thecover, providing a water tight seal. A drip shield is also in place to cover and protect the board in the event any water happensto get through. A bottom block off is also present to protect the board from any extremely high humidity conditions. Tomodify an existing piece of equipment in the field, either re-gasket around the access cover, or apply a sealer such as RTVsilicone sealant. Next, add two additional screws to each side of the cover panel, this should insure a water tight seal.


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40. Temperature Swings, Bounces Between Heating And CoolingA few microcontrol Voyager jobs have experienced excessive temperature swings in both the heating and cooling modes.Temperature swings reported and observed have been as large as plus and minus 3-3.5° F. (6-7° total). Temperature swingsmay occur when the unit is oversized for heating or cooling. The problem is worsened by a high number of required orconsequential air changes. The high number of air changes may be a product of Indoor Air Quality (IAQ) related specifications,or they may be specific to a certain application (restaurant, meeting hall, etc.).

Potentially Affected are Packaged Electric / Electrics, Packaged Heat Pumps, and Packaged Gas / Electrics with serial numberdate codes F49 through K48 in the following product models:

40.1. ZSM installation/location can accentuate zone temperature swings:Temperature swings may be caused by selecting a less than desirable Zone Sensor Module (ZSM) location. A good sensorlocation is near the return air grille, on an inside wall, and not being subjected to or influenced by any hot or cold sources.Temperature swings can also be created by poor ZSM installation practices. Problems are frequently caused by failure to sealthe wall penetration behind the sensor, or by installing locking covers over sensors. Sensors require adequate air flow to be ableto respond to changing room temperatures. After identifying a zone temperature swing condition, verify the following:

1. Verify that the ZSM is located near a return air grille.2. Verify that the ZSM is located on an inside wall.3. Verify that the ZSM is not being subjected or influenced by a hot or cold source.4. Verify that the wall penetration behind the ZSM has been properly sealed.5. Verify that a locking thermostat cover has not been installed over the ZSM. If a locking cover has been installed it must beremoved, or an alternate means (typically remote sensing) must be utilized.

Note: If a programmable ZSM is being used (BAYSENS012A, BAYSENS018A, BAYSENS019A/B, BAYSENS020A/B, orBAYSENS023A), check to ensure that the internal thermistor is exposed in the gap between the ZSM and the sub base, and nottucked behind the ZSM housing, shielding it from air flow in the zone.

After verifying and correcting any of the preceding ZSM related conditions, if the problem still persists, make the followingadjustment to the heat anticipation setting: Open the service disconnect that supplies power to the equipment. There are twoswitches (SW1 and SW2) located in the upper right hand corner on the Unitary Control Processor (UCP). Put both of theseswitches in the "ON" position (push downward), this will change the heat cycle timing. These switches function similar to theheat anticipator in conventional thermostats.

If problems continue to persist a different UCP is available, the MOD-0305 or later version. This UCP has the ability torespond to or compensate for application issues, in most cases, due to oversizing. This board has a 10 second control loop, and"NO" minimum on time for the gas heat cycle.Note: Some UCPs (BRD-0931, BRD-1007 & MOD-0143) force packaged Gas / Electrics (YCs) to have a four minute heatingminimum on time. This will result in approximately three minutes of active heating run time, as approximately one minute isconsumed by the ignition process. This four minute minimum on time will not be present in MOD-0305 or later version.


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41. Evaporator Coil Icing (3-25 ton)

41.1. Low ambient mechanical cooling with large quantities of outdoor air:The Voyager line of products (3-25 ton) do not come equipped with expansion valves. Instead, short orifices and capillary tubesare utilized, they are fixed restriction type flow control devices. Icing of the evaporator coil may occur when mechanicalcooling is utilized during low ambient conditions, and large quantities of outside air are introduced at the same time.

The Voyager line of products, applied with an economizer or motorized outside air damper accessory, are capable ofintroducing 0-50% outside air for minimum ventilation purposes. In standard comfort cooling applications, where nominalairflow is maintained, icing can be expected to occur if the entering air temperature at the evaporator coil drops belowapproximately 68° F. dry bulb / 57° F. wet bulb. Any time the suction temperature approaches 30 to 32° F. icing may occur.

41.2. Excessive amounts of bypass from discharge to return air intake:There are several items that can facilitate bypass conditions in a system, a few of the more common ones are listed below.

1. The selection and installation of supply air diffusers, and their proximity to return air grilles.2. Failure to properly install gasketing on a roofcurb.3. The use of a field or custom manufactured curb.4. The selection of a concentric duct package, and the installation practices utilized.

Here again, icing can be expected to occur if the entering air temperature at the evaporator coil drops below approximately 68°F. dry bulb / 57° F. wet bulb. Any time the suction temperature approaches 30 to 32° F. icing may occur.

41.3. Operating mechanical cooling under low air flow, or low refrigerant charge:The Voyager line of products have cataloged air flow as low as 20% under nominal system air flow, which equates toapproximately 320 CFM per ton, with 400 CFM per ton nominal. The standard system with no accessories should not operatemechanical cooling at any conditions below the following outline, or coil icing may occur.

Air Flow: 320 CFMOutdoor Ambient: 55 °F.Entering Air: 68° F. db / 57° F. wb

When operating a Voyager system under low, or reduced refrigerant charge conditions, coil icing may occur when the suctiontemperature reaches approximately 30 to 32° F. The saturated suction pressure will be approximately 55 psig or less.

41.4. Operating equipment in a process application, with a sub-cooled zone:When the Voyager products are applied on process cooling environment, like a warehouse. The zone cooling requirement maybe 60 to 65° F. Once again we may be in a situation where the coil entering air conditions may be below 68° F. db / 57° F. wb.The evaporator coil will ice on a standard Voyager product with no accessories or field modifications.

41.5. Failure or removal of Outdoor Air Sensor (OAS):If the standard Outdoor Air Sensor (OAS) on a Voyager product fails, or is removed to operate the system using the internaldefaults, evaporator coil icing will occur during low ambient operation.

When the Outdoor Air Sensor (OAS) is removed, several functions are disabled: Condenser fan cycling (12.5-50 Ton),Evaporator Defrost Control (EDC) function (3-25 Ton), Economizer (3-50 Ton) if present.


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42. Solutions To Evaporator Coil Icing (3-25 ton)

42.1. Installing a direct sensing evaporator defrost control (EDC):Since the Voyager products do not have a direct sensing means of keeping ice off of the evaporator coil, it may be necessary (incertain applications) to install an external, direct sensing Evaporator Defrost Control (EDC).

The accessory AY28X079 (SWT-0842) is a suitable choice for most applications. It opens on a temperature fall at 25° F. andcloses on a temperature rise at 60° F. It comes with a 60” capillary tube, which is embedded in the face of the evaporator coil,and 2 - 60” electrical leads. A quantity of one EDC is all that is required to properly protect the equipment, as the voyagerseries of products have intertwined coils for the dual circuit machines.

The following is a list of applications and operating conditions where it is recommended that an EDC be installed:

1. Voyager / VariTrac Comfort Manager installations (Low Air Flow/Bypass).

2. Voyagers with concentric duct packages (Bypass).

3. Low line voltage applications with 3-5 Ton Voyagers with direct drive motors (Low Air Flow).

4. High Latent heat load applications (Low Air Flow/Low Temperature Entering Air).

5. Applications with long duct runs, and large quantities of outside air (Low Air Flow/Low Temperature Entering Air).

6. Applications with fresh air requirements in excess of 25% (Low Temperature Entering Air), conditions at 68° F. db and 50%R.H.

7. Nominal air flow conditions (400 CFM/Ton), with entering air temperatures below 65° F., and ambients below 80° F.

8. Under air flow conditions (Below 320 CFM/Ton), with entering air conditions below 68° F. db and 50% R.H., and ambientsbelow 80° F.

9. Air balance conducted with minimum fresh air required, and pressure drop through outside air damper is greater thanoriginal estimate

Electrical Diagram For Installing An EDC In A Voyager System

LPC1 UCPLTB-13 ⊗ � � � CPR1 DISABLE

∩ J2-2Jumper

EDCLTB-14 ⊗ � � � J7-1 (24 VAC)

Jumper LPC2 J2-3

LTB-15 ⊗ � � � CPR2 DISABLE ∩

Note: Substitute LTB-15 For LTB-14 On Equipment Manufactured Prior To 06/93


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42.2. Modifying configuration of condenser fan cycling temps (12.5-25 Ton):The modification of the condenser configuration provides some flexibility. However, caution should be exercised any time thata change like this is made. A change that resolves a problem at one operating condition, may cause a problem at another.

The configuration inputs are set to cycle condenser fan motor #2 “OFF”, when the outdoor temperature drops below 60° F.In an application with low air flow which drives the suction pressure down, it may be permissible to change the configuration tocycle condenser fan #2 “OFF”, when the outdoor temperature drops below 70° F. This would drive the discharge and suctionpressures up. In an application with restricted condenser air flow which drives the discharge pressure up, it may be permissibleto change the configuration to cycle condenser fan #2 “OFF”, when the outdoor temperature drops below 50° F. This would aidin keeping the discharge pressure down.

Condenser Fan Cycling Configuration (Outdoor Temperature At Which ODF2 Will Cycle Off If Present)

Outdoor Input Input Input Temp. (°F.) J2-5 J2-6 J2-7

80 Degrees GND GND GND 70 Degrees GND GND OPEN 60 Degrees GND OPEN GND 50 Degrees GND OPEN OPEN 40 Degrees OPEN GND GND 30 Degrees OPEN GND OPEN 20 Degrees OPEN OPEN GND Continuous OPEN OPEN OPEN

GND = This Input Must Be Connected Or Shorted To Ground.OPEN = This Input Must Be Open, No Connection To Ground.

42.3. Installing a head pressure control device to modulate condenser fan speed:A head pressure control device is typically installed in applications which have a high internal heat gain, where 100% ofequipment mechanical cooling capacity is required year round. Some typical applications which would require a head pressurecontrol device are.

1. Telephone switch gear room2. Computer room3. Printing processes4. Photographic development processes5. Generic manufacturing process cooling

The low ambient kits which are utilized with the mid range Odyssey split systems (7.5-20 Ton) from Ft. Smith, can be use inthe Voyager products, they include the Hoffman 816-10DS head pressure control and a ballbearing motor.

Note: There are no head pressure control kits for Voyager products below 5 Tons. Contact Light Commercial ApplicationsWhenever A Head Pressure Control Device Is Required On A Voyager Product


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42.4. Installing hot gas bypass, liquid injection type:Hot gas bypass is applied in special applications only, typically in zones introducing large quantities of outside air, or in zonesusing discharge air control. It may also be used in applications where the mechanical cooling capacity of the equipment ismodulated to meet the varying load requirements of a zone, such as churches, and theaters.

The liquid injection hot gas bypass kits which are utilized with the mid range Odyssey split systems (7.5-20 Ton) from Ft.Smith, can be used in the Voyager products. They include pre-piped assemblies consisting of the hot gas bypass valve, de-superheating valve, and discharge line service valve for ease of installation.

The installers guide for the hot gas bypass kits have detailed piping diagrams of the respective split system models that they areapplied with. There are no detailed instructions or diagrams pertaining to installation in, or applications with Voyager rooftopunits. The installing contractor must be creative, and use the installation instructions for conceptual purposes only, as the kitsare pre-piped for installation in the mid range split systems..

The hot gas bypass valve is preset to maintain suction pressure at approximately 55 psig. These hot gas bypass kits should notbe installed on any circuit 4 tons and under.

Contact Light Commercial Applications Whenever Hot Gas Bypass Is Required On A Voyager Product.

42.5. Installing hot gas bypass, bypass to evaporator inlet:

If hot gas bypass to the evaporator inlet must be accomplished on a Voyager rooftop unit, there are several modifications andconsiderations.

Bypass to the evaporator inlet requires that the system being modified utilizes a TXV. Since the Voyager series of rooftops (3-25 tons) do not use TXVs as the flow control device, the capillary tubes (or short orifices whichever is applicable) must beremoved and the system must be retrofitted with a TXV, Distributor, Distributor Nozzle, and Distributor Tubes.

There is not an application bulletin with guidelines regarding this type of retrofit. All aspects of the conversion to a TXVand selection of Distributor Nozzle sizing must be accomplished in the field. For more detailed instructions and informationregarding hot gas bypass application and installation, reference the Trane: Reciprocating Refrigeration Manual.

Contact Light Commercial Applications Whenever Hot Gas Bypass Is Required On A Voyager Product.


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43. Conditions Which Can Cause Incomplete Heat Pump Defrost

43.1. OAS out of calibration/mis-located (Demand Defrost 3-7.5 Ton):If the Outdoor Air Sensor (OAS) is out of calibration or mis-located, the microprocessor may interpret the outdoor airtemperature to be warmer or colder than it actually is. This would have a direct impact on the defrost initiation and terminationpoints.

The accuracy of the sensor may be determined by disconnecting it from the system, and checking the calibration accuracy in anice bath. The resistive value of the sensor should equal approximately 32° F. (32.9 K ohms). If an ice bath is not available,measure the resistive value of the sensor and the ambient temperature at the sensor, and verify the correlation of the two values.The sensor accuracy should be +/- 10%.

43.2. CTS out of calibration/mis-located (Demand Defrost 3-7.5 Ton):If the Coil Temperature Sensor (CTS) is out of calibration or mis-located, the microprocessor may interpret the outdoor coiltemperature to be warmer or colder than it actually is. This would have a direct impact on the defrost initiation and terminationpoints also.

The accuracy of the sensor may be determined by disconnecting it from the system, and checking the calibration accuracy in anice bath. The resistive value of the sensor should equal approximately 32° F. (32.9 K ohms). If an ice bath is not available,measure the resistive value of the sensor and the ambient temperature at the sensor, and verify the correlation of the two values.The sensor accuracy should be +/- 10%.

The Coil Temperature Sensor (CTS) is located in the same place on the 3-7.5 Ton equipment. It is located in a well (3/8"copper tube), which is brazed to the lowest circuit entering the outdoor coil, during the heating mode.

43.3. DT out of calibration/mis-located (Time/Temp. Defrost 10-20 Ton):The Defrost Temperature switch (DT) is a bi-metal switch as opposed to a thermistor sensor. The switch should close on atemperature fall at 26° F., and open on a temperature rise at 66° F.

The Defrost Temperature switch is a little more difficult to test for calibration accuracy than a thermistor. The accuracy of theswitch may be determined by disconnecting it from the system, and checking the calibration accuracy in a freezer. The probefrom a digital thermometer should be affixed to the sensing portion of the switch, and the switch and the probe insulatedtogether. The switch should close at approximately 26° F., when removed from the freezer the switch should open when thetemperature rises to approximately 66° F.

The Defrost Termination switch (DT) is located in the same place on the 10-20 Ton equipment. It is located on the tube whichfeeds the bottom circuit of the outdoor coil, during the heating mode. The switch is located on compressor bearing circuit #1.


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44. UCP F1 Fuse Or TNS1 Transformer Over Current Device BlowsAll 24V AC circuits that leave the UCP are protected by both the UCP’s F1 fuse, and the TNS1 transformer over current device.If a problem arises that causes either of these two devices to blow or trip, the problem will be in one of 8 particular places. Tobegin the problem location process, remove power from the system at the equipment disconnect. Then, disconnect all plugsfrom the UCP. The circuits and devices associated, and procedures for locating the problem are outlined below.

1. Indoor fan contactor coil could be shorted or grounded: Junction J2 is located on the right hand side of the UCP, it is a 24pin junction and plug. Locate terminal J2-22, and measure the resistance from J2-22 to ground. If a direct short is present, thereis a problem in this circuit, in the wire itself, or in the indoor fan contactor coil. If a direct short is not present, there is noproblem in this circuit.

2. Compressor contactor coil(s) could be shorted or grounded: Junction J8 is located in the lower right hand corner of theUCP, it is a 4 pin junction. Locate terminal J8-1, and measure the resistance to ground. If this is a dual circuit unit, locateterminal J8-4, and measure the resistance to ground. If a direct short is present in either circuit, a problem exists in the circuit,the wire, or the compressor contactor. If a direct short is not present, no problem exist in either circuit.

3. UEM humidity sensor power supply could be shorted or grounded: Junction J2 is located on the right hand side of theUCP, it is a 24 pin junction. Locate terminal J2-20, and measure the resistance to ground. If a direct short is present, there is aproblem in this circuit, in the wire itself, or in the UEM. If a direct short is not present, there is no problem in this circuit.

4. UCP on board power supply could be shorted or grounded: First, make sure the F1 fuse on the UCP is good. J2 is locatedon the right hand side of the UCP, it is a 24 pin junction. Locate pin J2-1, and measure the resistance to ground. If a direct shortis present, a problem exists in the circuit. Replace the UCP. If a direct short is not present, no problem exist in this circuit.

Note: An alternative method is to remove all plugs from the UCP, except terminal J2-1 by rotating the plug 90° ccw andmaking a single connection to J2-1. If no problem is observed, connect the entire J2 plug. Continue adding plugs one at a time,until the problem surfaces to be isolated and diagnosed.

5. Gas heat control or ODF coil could be shorted or grounded: Junction J5 is located in the upper right hand corner of the UCP,it is a 3 pin junction. Locate terminal J5-3, and measure the resistance to ground. If a direct short is present, a problem exists inthe circuit, the wire, or the gas heat or outdoor fan relay circuit. If a direct short is not present, no problem exists in this circuit.

6. TCI power supply or Hi Temp input could be shorted or grounded: Junction J6 is located on the upper left hand side ofthe UCP, it is a 7 pin junction. If a TCI is installed, locate the plug associated with this junction. Locate terminal J6-1, andmeasure the resistance to ground. If a direct short is present, a problem exists in the circuit, the wire, or the TCI. If a direct shortis not present, there is no problem in this circuit.

7. Electric heat contactor coil has shorted or grounded: Junction J2 is located on the right hand side of the UCP, it is a 24 pinjunction. Locate terminal J2-22, and measure the resistance to ground. If a direct short is present, there is a problem in thiscircuit, the wire, in the indoor fan contactor coil, or the wiring that powers the electric heater contactor circuit. If a dire ct shortis not present, there is no problem in this portion of the circuit.

Junction J1 is located on the top left side of the UCP, it is a 24 pin junction. Locate terminal J1-22, and measure the resistanceto ground. Also locate the wire that is connected to the K5 relay (N.O.) terminal, and measure the resistance to ground. If adirect short is present in either circuit, there is a problem in that circuit, in the wire itself or in the electric heater contactorcoil(s). If a direct short is not present, there is no problem in this circuit, proceed to the next circuit.

Note: Output at J2-22 re-enters UCP at J1-21 and K5 relay common, exits at J1-22 via the K6 relay and K5 relay N.O.

8. CTI/Compressor Disable power supply could be shorted or grounded: Junction J7 is located on the lower left side of theUCP, it is a 11 pin junction. Locate terminal J7-1, and measure the resistance to ground. If a direct short is present, there is aproblem in this circuit, in the wire itself, or in the CTI, if present. If a direct short is not present, there is no problem in thiscircuit.


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45. Multiple UCP U5 Chip FailuresThe U5 chip illustrated below, is a 29V DC relay driver that is used to energize off board relays and the Zone Sensor Module(ZSM) LEDs. This chip will fail if AC voltage is applied to one of its outputs, or if an output is grounded or over powered.

U5

45.1. Factory or Field mis-wire of AC voltage to U5 chip:A factory or field mis-wire, or arbitrary jumpering of the terminals, at the LTB may result in the accidental application of 24VAC to one of the U5’s 29V DC outputs. If this occurs, the negative half wave of the AC voltage will fail the U5 chip. A failedchip can be easily identified, a piece of the chip may be missing (looks like a crater in the chip), or a bubble or crack willappear in the chip.

45.2. Replacing defrost or condenser fan DC relays, with AC coils:The coil is 24V DC, not 24V AC. If AC relay coils are applied on these DC circuits, without modifications, it will ultimatelyfail the U5 chip and the relay. The relay coil would overheat and the wire insulation would burn off, causing the coil to short,pulling excessive current (over powering the output) and eventually causing complete failure. If U5 chip failures occur, checkfor wiring errors, both field and factory at the LTB.

Note: It is not apparent in the equipment electrical wiring diagrams or functional unit part’s list, as to what the coil voltage maybe on a particular relay.


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46. Multiple UCP U6 Chip FailuresThe U6 chip illustrated below, is a 29V DC relay driver that is used to energize on board and off board relays. This chip willfail if an output is grounded or over powered.

U6

46.1. Failure to install edge protector on a raw metal edge (Voyager 3-25):There is a short piece of edge protector, which ships with every economizer/motorized outside air damper accessory. The pieceof edge protector is included in the plastic "bag of parts" which comes with the accessory. It is intended that the piece of edgeprotector be installed on any raw metal edge that the accessory wiring harness must be routed over. Failure to install the edgeprotector, can result in the raw metal edge slicing through the wiring harness. The problem may surface immediately, or it maybecome evident over time with equipment operational vibration. Remove power from the equipment and inspect the accessorywiring harness where it passes over metal, look for damage to the insulation on the conductors, repair conductors and protectthem from further damage by isolating them from the metal.

46.2. Wiring harness damaged in factory installation (Voyager 3-25):When the equipment wiring harness is installed in the unit, a portion of the wiring harness must be routed from the control boxinto the evaporator blower section. This section of the wiring harness is for the indoor fan motor, and economizer / motorizedoutside air accessory. The wiring harness must pass through two bulkhead, or block off panels, before reaching the evaporatorblower section. If the insulation on the conductors was damaged as the harness was installed, it may result in a conductorshorting to ground. The problem may surface immediately, or it may become evident over time with equipment operationalvibration. Remove power from the equipment and inspect the equipment wiring harness where it passes through each metalblock off. Look for damage to the insulation on the conductors, repair conductors and protect them from further damage byisolating them from the metal.

46.3. Replacing power exhaust relay, with AC coil relay:The coil is 24V DC, not 24V AC. If an AC relay coil is applied on this DC circuit, without modifications, it will ultimately failthe U6 chip and the relay. The relay coil would overheat and the wire insulation would burn off, causing the coil to short,pulling excessive current (over powering the output) and eventually causing complete failure. If U6 chip failures occur, checkfor wiring harness damage, both unit harness and economizer / motorized outside air damper harness.

Note: It is not apparent in the equipment electrical wiring diagrams or functional unit part’s list, as to what the coil voltage maybe on a particular relay.


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Section 6

47. Pin Descriptions & Voltages

47.1. Voltages And Descriptions Available At The LTB, Prior To 06/93

Note: Factory Jumpers Installed Across Terminals: LTB-13, 15, And 17. (Voltages Are Measured With Wires Disconnected).

47.2. Voltages And Descriptions Available At The LTB, After 06/93 (3-50 ton)

Note: Factory Jumpers Installed Across Terminals: LTB-13, 14, And 15 / LTB-16 And 17 / LTB-18 And 19. (Voltages AreMeasured With Wires Disconnected).


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47.3. Voyager 27.5-50 Ton LTB-2 Pin Descriptions & Voltages




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47.6. UCP Pin Descriptions & Voltages 3-25 Ton

PIN VOLTS INFORMATIONJ1-1 *Common Digital Common Shorting Point for Config. InputsJ1-2 & J1-3 0 VDC Input Inputs used to determine Unit Type TC,TW,YCJ1-4 0 VDC Input Inputs used to determine 1 or 2 Compressor SystemJ1-5 24 VAC Input Heat Fail Input for Gas/ElectJ1-6 No PinJ1-7 0 VDC Input Input to Enable/Disable Power SlasherJ1-8 32 VDC Output Output to Power Slasher 2 Speed Fan Relay, 32 VDC when relay "not" energizedJ1-9 29 VDC Output Output to Power Slasher 2 Speed Fan Relay if presentJ1-10 No PinJ1-11 32 VDC Output Output to ODF 2 Relay, 32 VDC present when "NOT" energizedJ1-12 29 VDC Output Output to ODF2 Relay if presentJ1-13 32 VDC Output Output to SOV Relay or Heat 3, 32 VDC present when relay "NOT" energizedJ1-14 29 VDC Output Output to SOV Relay on Heat Pumps or Heat 3 if presentJ1-15 5 VDC Input Outdoor Air Sensor Analog InputJ1-16 *Common Analog Common for OASJ1-17 No PinJ1-18 *Common Digital Common Shorting Point for Config. InputsJ1-19 & J1-20 0 VDC Input Inputs used to determine # of Heat Stages, for a particular unit typeJ1-21 24 VAC Input Heat 1 Input provides Power for Heat 1 OutputJ1-22 24 VAC Output Output to energize Stage 1 HeatJ1-23 Not UsedJ1-24 29 VDC Output Continuos 29 VDC Output, Spare Pin (NOT USED)

J2-1 24 VAC Input UCP Power Supply InputJ2-2 24 VAC Input CPR 1 Disable Ckt.J2-3 24 VAC Input CPR 2 Disable Ckt.J2-4 No PinJ2-5, 6 & 7 32 VDC Input Inputs used with one another to determine Condenser Fan Cycling Temp.J2-8 5 VDC Output Binary Output to UEM to drive ECA open (1.7 V when driving)J2-9 5 VDC Output Binary Output to UEM to drive ECA closed (1.7 V when driving)J2-10, 11 & 12 5 VDC Output Analog/digital Output to UEM, tells UEM which data it wants to read on J2-15 InputJ2-13 29 VDC Output (Pulsing) Output to UEM for XFC, 29 VDC present when XFC is "NOT" energized


140

J2-14 29 VDC Output Output to UEM for XFC, continuos 29 VDC OutputJ2-15 5 VDC Input (Pulsing) Communication Input from UEMJ2-16 5 VDC Output Analog Reference Voltage to UEMJ2-17 *Common Analog Common to UEMJ2-18 *Common Digital Common to UEMJ2-19 5 VDC Output 5 VDC Power Supply to UEMJ2-20 24 VAC Output Power Supply for Humidity Sensor CircuitsJ2-21 5 VDC Output Output to Coil Temp. Sensor, or Defrost ModuleJ2-22 24 VAC Output Output to energize Supply Fan ContactorJ2-23 No PinJ2-24 *Common UCP Power Common

J4-1 5 VDC Input Mode Initiation Analog InputJ4-2 *Common Analog Common (LTB-TEST-2), Shorting point for config inputs

J5-1 24 VAC Input Fan/Filter status input for indicationJ5-2 No PinJ5-3 24 VAC Output Output to LTB-18 used for Heat Fail input, YCs Only

J6-1 24 VAC Output TCI Power Supply for High Temp. Switch InputJ6-2 32 VDC Output Output to TCI Power SupplyJ6-3 5 VDC Input TCI Installed, read unit address digital inputJ6-4 5 VDC Output Transmit Data, Binary Output to TCIJ6-5 5 VDC Output Transmit Enable, Binary Output to TCIJ6-6 32 VDC O/I (Pulsing) Output to LTB-12, Receive data line for programmable ZSM or TCI if installedJ6-7 *Common Digital Common to LTB-11 for programmable ZSM & TCI

J7-1 24 VAC Output Output to LTB-14, CPR 1 & 2 Disable & Fan Filter StatusJ7-2 *Common Power Common to ZSM LEDs/LCDsJ7-3 *Common Analog Common to ZSM Control CircuitJ7-4 32 VDC Output Output to LTB-10 for ZSM Service LED/LCDJ7-5 32 VDC Output Output to LTB-8 for ZSM Cool LED/LCDJ7-6 32 VDC Output Output to LTB-7 for ZSM Heat LED/LCDJ7-7 32 VDC Output Output to LTB-9 for ZSM Sys On LED/LCDJ7-8 5 VDC Input ZSM Cooling Set Point Analog InputJ7-9 5 VDC Input ZSM Heating Set Point Analog InputJ7-10 5 VDC Input ZSM Mode Analog InputJ7-11 5 VDC Input ZSM Zone Temp. Analog Input

J8-1 24 VAC Output Output to Energize Compressor Contactor CC1J8-2 No PinJ8-3 No PinJ8-4 24 VAC Output Output to Energize Compressor Contactor CC2

* Common to Chassis Ground


141

47.7. UCP Pin Descriptions & Voltages 27.5-50 Ton

PIN VOLTS INFORMATIONJ1-1 *Common Digital Common Shorting Point for Config. InputsJ1-2 0 VDC Input Inputs used to determine Heat ConfigurationJ1-3 0 VDC Input Daytime Warm-up Heat ConfigurationJ1-4 0 VDC Input Inputs used to determine Number of CompressorsJ1-5 24 VAC Input Heat Fail InputJ1-6 No PinJ1-7 0 VDC Input Lead/Lag ConfigurationJ1-8 Pin Not UsedJ1-9 29 VDC Output Output to Power Slasher Fan RelayJ1-10 No PinJ1-11 32 VDC Output Output to ODF 2 Relay, 32 VDC present when "NOT" energizedJ1-12 29 VDC Output Output to ODF2 RelayJ1-13 32 VDC Output Output to VAV Boxes or Heat 3J1-14 29 VDC Output Output to SOV Relay Heat 3J1-15 5 VDC Input Outdoor Air Sensor Analog Input/ UVM Analog ExpansionJ1-16 *Common Analog Common for OASJ1-17 No PinJ1-18 *Common Digital Common Shorting Point for Config. InputsJ1-19 0 VDC Input Input used to determine 2 Heat/ Cool Stages, for a particular unit typeJ1-20 0 VDC Input Input used to determine 1 Heat Stage, for a particular unit typeJ1-21 24 VAC Input Heat 1 Input provides Power for Heat 1 OutputJ1-22 24 VAC Output Output to energize Stage 1 HeatJ1-23 24 VAC Output Output to energize Stage 2 HeatJ1-24 29 VDC Output Relay Drive

J2-1 24 VAC Input UCP Power Supply InputJ2-2 24 VAC Input CPR 1 Disable Ckt.J2-3 24 VAC Input CPR 2 Disable Ckt.J2-4 32 VDC Input Condenser Fan AJ2-5 32 VDC Input Inputs used for Condenser Fan Cycling 1J2-6 32 VDC Input Supply Fan Proving


142

J2-7 32 VDC Input Inputs used for Condenser Fan Cycling 3/ Emergency StopJ2-8 5 VDC Output Binary Output to UEM to drive ECA open (1.7 V when driving)J2-9 5 VDC Output Binary Output to UEM to drive ECA closed (1.7 V when driving)J2-10, 11 & 12 5 VDC Output Analog/digital Output to UEM or UVM, tells UEM or UVM which data it wants to readJ2-13 29 VDC Output (Pulsing) Output to UEM for XFC, 29 VDC present when XFC is "NOT" energizedJ2-14 29 VDC Output Output to UEM for XFC, continuos 29 VDC OutputJ2-15 5 VDC Input (Pulsing) Communication Input from UEMJ2-16 5 VDC Output Analog Reference Voltage to UEMJ2-17 *Common Analog Common to UEMJ2-18 *Common Digital Common to UEMJ2-19 5 VDC Output 5 VDC Power Supply to UEM or UVMJ2-20 24 VAC Output Power Supply for Humidity Sensor CircuitsJ2-21 5 VDC Output Output to Outside Air Temperature BiasJ2-22 24 VAC Output Output to energize Supply Fan ContactorJ2-23 No PinJ2-24 *Common UCP Power Common

J4-1 5 VDC Input Test InputJ4-2 *Common Analog Common (LTB-TEST-2), Shorting point for config inputs

J5-1 24 VAC Input Clogged Filter status input for indicationJ5-2 No PinJ5-3 24 VAC Output Output to LTB-18 used for Heat Fail input, YCs Only

J6-1 24 VAC Output TCI Power Supply for High Temp. Switch InputJ6-2 32 VDC Output Output to TCI Power SupplyJ6-3 5 VDC Input TCI Installed, read unit address digital inputJ6-4 5 VDC Output Transmit Data, Binary Output to TCIJ6-5 5 VDC Output Transmit Enable, Binary Output to TCIJ6-6 32 VDC O/I (Pulsing) Output to LTB-12, Receive data line for programmable ZSM or TCI if installedJ6-7 *Common Digital Common to LTB-11 for programmable ZSM & TCI

J7-1 24 VAC Output Output to LTB-14, CPR 1 & 2 Disable & Fan Filter StatusJ7-2 *Common Power Common to ZSM LEDs/LCDsJ7-3 *Common Analog Common to ZSM Control CircuitJ7-4 32 VDC Output Output to LTB-10 for ZSM Service LED/LCDJ7-5 32 VDC Output Output to LTB-8 for ZSM Cool LED/LCDJ7-6 32 VDC Output Output to LTB-7 for ZSM Heat LED/LCDJ7-7 32 VDC Output Output to LTB-9 for ZSM Sys On LED/LCDJ7-8 5 VDC Input ZSM Cooling Set Point/Supply Air Cooling Set Point Analog InputJ7-9 5 VDC Input ZSM Heating Set Point /Supply Air Reset Set Point Analog InputJ7-10 5 VDC Input ZSM Mode Analog InputJ7-11 5 VDC Input ZSM Zone Temp. /Supply Air Temp. Analog Input

J8-1 24 VAC Output Output to Energize Compressor Contactor CC1J8-2 24 VAC Ground Compressor Contactor CC1 Return; measures amp draw of coilJ8-3 24 VAC Ground Compressor Contactor CC2 Return; measures amp draw of coilJ8-4 24 VAC Output Output to Energize Compressor Contactor CC2

J9-1, 3 24 VAC Input Power for Compressor ContactorsJ9-2, 4 Pin Not Used

J10-1 24 VAC Input FrostatJ10-2 24 VAC Input Ventilation Override InitiateJ10-3 5 VDC Output IGV/VFD Pulse Width Modulating Output


143

47.8. UEM Pin Descriptions & Voltages 3-50 Ton

PIN VOLTS INFORMATIONJ1-1 5 VDC Input Analog Reference Voltage, Input from UCPJ1-2 Common UEM Digital Common

J1-3 Common UEM Analog CommonJ1-4 5 VDC Output Analog Output, Communication Link to UCPJ1-5, 6, & 8 5 VDC Input Digital Input from UCP, tells UEM what data it wants to read on Output J1-4

J1-7 No PinJ1-9 5 VDC Input 5 VDC Power Supply Input from UCP

J1-10 5 VDC Input Binary Input from UCP to Drive ECA Closed

J1-11 5 VDC Input Binary Input from UCP to Drive ECA Open

J1-12 29 VDC Output Input from UCP Directly Controls XFP, 29 VDC present when XFC is "NOT" energized

J1-13 24 VAC Input Input form UCP which provides power for the Humidity SensorJ1-14 29 VDC Output Input from UCP Directly Controls XFP, 29 VDC continuously present

J2-1 5 VDC Input Analog Input for Supply Air Sensor

J2-2 Common Analog Common for Supply Air Sensor

J3-1 5 VDC Input Analog Input for Return Air Sensor

J3-2 Common Analog Common for Return Air Sensor

J4-1 5 VDC Output Analog Reference Voltage, Output to DFM

J4-2 5 VDC Input Analog Input from DFM for Time/Temp Defrost, or CTS for Demand Defrost

J4-3 Common Analog Common to DFM, or CTS for Demand Defrost

J5-1 Pin Not UsedJ5-2 No PinJ5-3 5 VDC Input Binary Input for Fan Failure Switch, or Analog Input for ECA Feedback Pot.

J5-4 Common Analog Common for Fan Failure Switch or ECA Feedback Pot.

J5-5 Common Digital Common for J5-7 & J5-8, Common Outputs to Drive ECA Open & Closed

J5-7 Common Output to ECA, internally makes connection to Common to Drive ECA Closed

J5-8 Common Output to ECA, Internally makes connection to Common to Drive ECA Open

J6-1 29 VDC Output Direct Output from UCP to XFC, 29 VDC continuously present

J6-2 29 VDC Output Direct Output from UCP to XFC, 29 VDC present when XFC is "NOT" Energized

J7+ 4-20 mA Input For Return Humidity SensorJ8+ 20 VDC Input 20 VDC Supply for Return Humidity SensorJ9+ 4-20 mA Input Outdoor Humidity SensorJ10+ 20 VDC Input 20 VDC Supply for Outdoor Humidity SensorJ11 5 VDC Input Analog Input for Remote Minimum Position Pot.J12 Common Analog Common for Remote minimum Position Pot.


144

47.9. UVM Pin Descriptions & Voltages 27.5-50 Ton

PIN VOLTS INFORMATIONJ1-1 5 VDC Input Analog Reference Voltage, Input from UCPJ1-2 Common UVM Digital CommonJ1-3 Common UVM Analog CommonJ1-4 5 VDC Output Analog Output, Communication Link to UCPJ1-5, 6, 8 5 VDC Input Digital Input from UCP, tells UVM what data it wants to read on OutputJ1-7 No PinJ1-9 5 VDC Input 5 VDC Power Supply Input from UCPJ1-10 Pin Not UsedJ1-11 0-10 VDC Output IGV/VFDJ1-12 Pin Not Used

J1-13 24 VAC Input Provides supply voltage for 0-10 VDC OutputJ1-14 Pin Not Used

J2-1 5 VDC Input Analog Input for Outdoor Air TemperatureJ2-2 Common Analog Common for Outdoor Air Sensor

J3-1 5 VDC Input Analog Input for Zone TemperatureJ3-2 Common Analog Common for Zone Temperature Sensor

J4-1 5 VDC Output Analog Reference Voltage, Output to MWU Set pointJ4-2 5 VDC Input Morning Warm Up Set PointJ4-3 Common Analog Common

J5-1 Pin Not UsedJ5-2 No PinJ5-3 5 VDC Input Static Pressure DeadbandJ5-4 Common Analog CommonJ5-5 Common Digital CommonJ5-6 Pin Not UsedJ5-7 Pin Not UsedJ5-8 0-10 VDC Output IGV/VFD

J7+ 0-5 V Input Reset Set PointJ8+ Common Analog CommonJ9+ 0-5 V Input Pressure TransducerJ10+ 5 VDC Input 5 VDC Supply for Pressure TransducerJ11 0-5 V Input Static Pressure Set PointJ12 Common Analog Common for Static Pressure Set Point


145

47.10. VAV Set Point Panel 27.5-50 TonFront of Panel

Back of Panel


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47.11. DFM Pin Descriptions & Voltages 3-20 Ton

PIN VOLTS INFORMATIONJ1-1 29 VDC Input Input from UCP to DFM K1 Relay Coil, 29 VDC continuously presentJ1-2 29 VDC Input Input from UCP to DFM K1 Relay Coil, 32 VDC present if relay is NOT energized

J2-1 Common Analog Common from UCP, or UEM if presentJ2-2 Common DFM Power CommonJ2-3 5 VDC Output Analog Output to UCP, or UEM if presentJ2-4 No PinJ2-5 5 VDC Input Analog Reference Voltage Input from UCP or UEM if present

J3 24 VAC Output Output from DFM K1 Relay Normally Open, Energizes SOV(S)J4 24 VAC Input Input from TNS3 Secondary to KI Relay Contact Common, provides power to energize SOVsJ5 24 VAC Output Output from DFM K1 Relay Normally Open, Share Output Energized if SOVs are EnergizedJ6 24 VAC Input Input from Defrost (Termination) Temperature Switch

47.12. CTI Pin Descriptions & Voltages 3-50 Ton

PIN VOLTS INFORMATIONJ1-1 24 VAC Output Output to LTB-15, LTB-14 on units manufactured after 06/93, provides input through Tstat to LTBJ1-2,3,4 Not UsedJ1-5 24 VAC Input Input from LTB-8, for Heat PumpJ1-6 24 VAC Input Input from LTB-7, for Heat Pump or Heat/CoolJ1-7 24 VAC Input Input from LTB-9, for Heat PumpJ1-8 24 VAC Input Input from LTB-3, for Heat Pump or Heat/CoolJ1-9 24 VAC Input Input from LTB-5, for Heat/CoolJ1-10 24 VAC Input Input from LTB-4, for Heat Pump or Heat/CoolJ1-11 24 VAC Input Input from LTB-1, for Heat Pump or Heat/Cool

J2-1 Common Output to UCP CSP InputJ2-2 5 VDC Output Output to UCP CSP InputJ2-3 5 VDC Output Output to UCP HSP InputJ2-4 5 VDC Output Output to UCP ZTEMP InputJ2-5 5 VDC Output Output to UCP MODE of Operation InputJ2-6 24 VAC Input 24 VAC power supply, provides power to CTI Output J1-1


147

47.13. TCI-1 Pin Descriptions & Voltages 3-50 Ton

PIN VOLTS INFORMATIONJ1-1 Common Digital Common from UCPJ1-2 Pulsating 32VDC Output Output to UCP, receive data lineJ1-3 5 VDC Input Transmit enable binary Input from UCPJ1-4 5 VDC Input Transmit data, binary Input from UCPJ1-5 5 VDC Input Digital Input from UCP. TCI Installed/Read Unit AddressJ1-6 32 VDC Input Input from UCP, TCI Power SupplyJ1-7 24 VAC Input Input from UCP provides power to TB2-2 for Output to High Temp Switches

TB-1 & 2 Pulsating 6VDC Input Input from ICS device comm link, must be measured with an Oscilloscope

TB2-1 24 VAC Output Input from High Temp Switches if presentTB2-2 24 VAC Output Output to High Temp Switches if present


PIN VOLTS INFORMATIONJ1-1 Common Digital Common from UCPJ1-2 Pulsating 32VDC Output Output to UCP, Receive data lineJ1-3 5 VDC Input Transmit enable, binary Input from UCPJ1-4 5 VDC Input Transmit data, binary Input from UCPJ1-5 5 VDC Input Digital Input from UCP, TCI Installed/Read unit addressJ1-6 32 VDC Input Input from UCP, TCI power supplyJ1-7 24 VAC Input Input from UCP provides power to TB2-2 for Output to High Temp Switches

J3 Common Chassis Ground

TB1-1 & 2 Pulsating 6 VDC Input Input from ICS device comm link, must be measured with an Oscilloscope



148


PIN VOLTS INFORMATIONJ1-1 Common Digital Common from UCPJ1-2 Pulsating 32VDC Output Output to UCP, receive data lineJ1-3 5 VDC Input Transmit enable, binary Input from UCPJ1-4 5 VDC Input Transmit data, binary Input from UCPJ1-5 5 VDC Input Digital Input from UCP, TCI Installed/Read unit addressJ1-6 32 VDC Input Input from UCP, TCI Power SupplyJ1-7 24 VAC Input Input from UCP provides power to TB2-2 for Output to High Temp Switches

J3 Common Chassis Ground

TB1-1 & 2 Pulsating 6 VDC Input Input from ICS device comm link, must be measured with an Oscilloscope



149

48. Low Voltage Identification Through Wire Color Coding (3-25 only)

BLACK = Output Or Input For Devices Not Used In Cooling ModeBLUE = Common To Chassis Ground For All Low Voltage AC & DCBROWN = Output Or Input For Heat Devices And ConfigurationGREEN = Chassis GroundPURPLE = Input To UCP And UEM, Binary Or AnalogRED = 24 Volt AC PowerYELLOW = Cooling Function Output, Mechanical Or Economizer

Note: Voyager 27.5-50 ton low voltage wires are all black only.

Wire Color Voltage Description And Identification

BLACK (BK) 24 Volts AC Output To Indoor Fan Contactor (F). Output And

Input 32 Volts DC Output To TCI, And ZSM LEDs/LCDs.

29 Volts DC Output To UEM, DFM, And Defrost Relay (DFR).

5 Volts DC Output To UEM, TCI, And DFM. Input To UEM From SAS.

BLUE (BL) Ground TNS1 Transformer Common, Common ToCommon All Low Voltage, Common To Ground.

BROWN (BR) 24 Volts AC Output To 24 Volt AC Heat Controls. Heat Output And Input 5 Volts DC Input (Configuration) For Available Number Of Heat Stages,

TCs And WCs.

GREEN (GR) Ground Chassis Ground.

PURPLE (PR) 24 Volts AC Input CPR1 Disable, CPR2 Disable, And Fan Filter StatusInput (Binary).

20 Volts DC Input To UEM For OHS And RHS.

5 Volts DC Input, Binary And Analog For System Configuration And Operation. Input To UEM For RAS, And AFF.

RED (RD) 24 Volts AC Power For UCP, UEM, TCI, ECA, CTI, DFM, CPR1 & CPR2 24VAC Power Disable, And Fan / Filter Status.

YELLOW (YL) 5 Volts DC Output To UEM To Drive ECA Open And Closed. UCP Cool Output Analog Input For CTS On 3-7.5 Ton WCs Only.

24 Volts AC Output To CC1, CC2, LPC2, UEM, And ECA.

29 Volts DC Output To ODF, WCs Only.


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49. General Specifications Of Control Components

Component Voltage Range Operating VA Notes And Comments (UCP) 18-30 Volts AC, Inrush = Inrush Is Power Up With Multiple Components Unitary 24 VAC Nominal. 126 VA Energized. Sealed is Steady State VA During Normal Control Sealed = Operation. Measure VA At Wire #32A (RED), If Processor 14 VA Manufactured Prior To 06/93 At Wire #34A (RED).

(UEM) 18-30 Volts AC, Inrush = Inrush is Steady State VA With Power “ON”, Unitary 24 VAC Nominal. 1.5 VA And Dampers Not Moving (UEM LED is “OFF”). Economizer 4.75-5.25 Volts DC, Sealed = Sealed is Steady State VA With Dampers Driving

Module 5.0 VDC Nominal. 3.0 VA Open Or Closed (UEM LED is “ON”).

(UVM) 18-30 Volts AC, Inrush = Inrush is Steady State VA. Unitary 24 VAC Nominal. 1.5 VA VAV 4.75-5.25 Volts DC, Sealed =

Module 5.0 VDC Nominal. 3.0 VA

(CTI) 18-30 Volts AC, Inrush = Power Consumption By The CTI is A ConstantConventional 24 VAC Nominal. 12.5 VA 12.5 VA, When Power is Applied To The Unit.

Thermostat Sealed = Interface 12.5 VA

(DFM) 18-30 Volts AC, Inrush = Power Consumption By The DFM is A Constant Defrost 24 VAC Nominal. Less Than 1.5 VA Or Less, When Power is Applied To The Unit. Module 4.75-5.25 Volts DC, 1.5 VA (10-20 tons) 5.0 VDC Nominal. Sealed = 20.6-31.2 Volts DC, Less Than 29 VDC Nominal. 1.5 VA

(TCI) 18-30 Volts AC, Inrush = Power Consumption By The TCI is A Constant Trane 24 VAC Nominal. 3.5 VA 3.5 VA, When Power is Applied To The Unit. Communication 22.1-42.1 Volts DC, Sealed = Interface 32 VDC Nominal. 3.5 VA

(ECA) 18-30 Volts AC, Inrush = Inrush is Power Consumption While The ECA Economizer 24 VAC Nominal. 8.0 VA is Driving Open/Closed. Sealed is Power Consumption Actuator Sealed = While The ECA is Stationary Or Holding A Position. 4.0 VA Measure VA At Wire #32B (RED), IfManufactured Prior To 06/93 At Wire #34D (RED).

(IGN) 18-30 Volts AC, Inrush = Power Consumption By The IGN (Fenwal Ignition 24 VAC Nominal. 2.4 VA Model #05-24) is A Constant 2.4 VA, Anytime That

Control Sealed = The Heat Mode is Activated. Module 2.4 VA

(IGN) 18-30 Volts AC, Inrush = Inrush is Power Consumption Of The IGNIgnition 24 VAC Nominal. 4.0 VA When The System is Actively Heating. Sealed isControl Sealed = Power Consumption When The IGN is in Stand By,Module 2.4 VA Or Not Actively Heating. The IGN is Always Powered

(Texas Instruments Model #3HS-B4).

1. This chart is useful for locating over current problems which open UCP and transformer fuses / breakers.2. To calculate VA, VA = Volts x Amps (Or Watts).3. The VA consumption for individual components must be measured along with the UCP VA. Add and delete components byconnecting and disconnecting plugs, adding and subtracting VA values to the base line UCP measurement.4. All VA measurements listed in this table are worst case.


151

50. Microcontrol Printed Circuit Board Switch SettingsAs a simplification all printed circuit boards are shipped with the on board switches set in the OFF position, this is the factorysetting. The OFF position means that all switches are pushed toward the outside edge of the P.C. board.

50.1. Unitary Control Processor (UCP) Switch Setting Table

Switch Switch Heat Anticipation VAV Configuration1 2 (3-50 Ton CV) (27.5-50 Ton VAV)

OFF OFF Normal (Default) Inlet Guide VanesOFF ON Shorter N/AON OFF Longer Variable Frequency DrivesON ON Special * N/A

* The Special setting is used when a very short heating cycle is required, typically used when the equipment heat capacity isover sized for the application, will help alleviate heating temperature swings.

50.2. Unitary Economizer Module (UEM) Switch Setting Table

Switch Switch Dry Bulb (°F.) Selected Standard 1 2 Temperature Enthalpy Setting

OFF OFF 60 Factory 19 Btu/LB dry air D Factory OFF ON 55 22 Btu/LB dry air C Default ON OFF 65 25 Btu/LB dry air B ON ON 70 28 Btu/LB dry air A

50.3. Defrost Module (DFM) Switch Setting Table (10-20 ton)

Switch Switch Defrost Time 1 2 Interval

OFF OFF 70 Min. (Default) OFF ON 90 Min. ON OFF 60 Min. ON ON 45 Min.

50.4. Unitary Variable Air Volume Module (UVM) switch settings (27.5-50 ton)

Switch Switch Reset Setting1 2

OFF OFF No Supply Air Temperature Reset (Default)OFF ON Return Air Temperature ResetON OFF Zone Temperature ResetON ON Outdoor Air Temperature


152

51. UCP Configuration Input (3-25 ton) Unit Type Configuration Heat Stage Configuration

Unit Input Input Number Of Input InputType J1-2 J1-3 Heat Stages J1-19 J1-20

TC GND GND YC 1 Stage OPEN GND WC Time/Temp GND OPEN YC 2 Stages GND OPEN YC OPEN GND TC 0-1 Stage GND GND

WC Demand Defrost OPEN OPEN TC 2 Stages GND OPEN TC 3 Stages OPEN OPEN WC 0-1 Stg Aux OPEN GND WC 2 Stg Aux OPEN OPEN

Compressor LEAD/LAG Configuration Cooling Staging ConfigurationEnable / Disable Input Number Of Available Input

Function J1-7 Compressors J1-4

Enable OPEN One Compressor GND Disable GND Two Compressors OPEN

Condenser Fan Cycling Configuration (Outdoor Temp. At Which ODF2 Will Cycle Off If Present) Outdoor Input Input Input Temp. (°F) J2-5 J2-6 J2-7

80 Degrees GND GND GND 70 Degrees GND GND OPEN 60 Degrees GND OPEN GND 50 Degrees GND OPEN OPEN 40 Degrees OPEN GND GND 30 Degrees OPEN GND OPEN 20 Degrees OPEN OPEN GND Continuous OPEN OPEN OPEN

GND = This Input Must Be Connected Or Shorted To Ground. OPEN = This Input Must Be Open, No Connection ToGround.

52. UCP Configuration Input (27.5-50 ton) Heat Configuration Cool ConfigurationUnit Input Input Unit Input Type J1-20 J1-2 Type J1-19

Cool Only GND NA VAV GNDGas Heat OPEN OPEN CV OPENElectric Heat OPEN GND

Compressor LEAD/LAG Configuration Cooling Staging ConfigurationEnable / Disable Input Number Of Available Input

Function J1-7 Compressors J1-4

Enable OPEN 3 Compressors (27.5-35 ton) OPEN Disable GND 3 Compressors (40-50 ton) GND

Condenser Fan Cycling Configuration*Reference 1.1.10


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53. UCP “Snubber Circuits”The Unitary Control Processor (UCP) may have up to six (6) relays located on the front of the printed circuit board. Theserelays are used to turn Alternating Current (AC) loads “ON” and “OFF”. The purpose of the Snubber Circuit is to act as a filter,to help dampen the voltage peaks associated with the opening and closing of the relay contacts. The Snubber Circuit is an R/C(Resistive / Capacitate) circuit, with a resistor and capacitor wired in series across the relay contacts.

Resistor Capacitor�/\/\/\/\� � | ( �

24 Volt ACOutput To Load Relay Contacts 24 Volt ACBeing Controlled � � | | � � Power Supply(“Off Board”) (“On” Board)

Snubber Circuits may cause confusion, because 24 VAC will be present if the output wire is disconnected from the load (relayor contactor coil) and the relay contacts are open. The voltage potential between the disconnected wire and ground will be 24VAC, but no current is present. When the wire is placed back on the contactor coil, the 24 VAC potential will disappear.

The relays located on the UCP are numbered and identified as K1 through K6, the output relays are used to turn on “Off” board(24 VAC) loads such as relays and contactors. The relays are designated and dedicated as follows:

Relay Relay Contact Contact Output Relay# Type Ratings Type To Pin # DesignationK1 Sealed 2A @ 24 VAC SPDT / N.O. J8-1 Circuit 1

K2 Sealed 2A @ 24 VAC SPDT / N.O. J8-4 Circuit 2

K3 Sealed 2A @ 24 VAC SPDT / N.O. J2-22 Supply Fan

K4 Sealed 30A @ 240 VAC SPST / N.O. 1/4” Terminals Condenser Fan

K5 Sealed 20A @ 240 VAC SPDT / N.O. 1/4” Terminals Heat 210A @ 240 VAC N.C. 1/4” Terminals

K6 Sealed 2A @ 24VAC SPDT / N.O. J1-22 Heat 1J1-21 Common

Notes:1. Relays K1, K2, K3 and K6 contacts are rated 5A @ 120 VAC by the manufacturer, they are derated to 2A @ 24 VAC. 2. Relays K1, K2, K3 and K6, there is no internal connection (on the UCP) to the N.C. contact.3. Relay K6 common terminal is not internally powered by the UCP.

Physical Relay Location On The UCP

K5 K4 K6 K3 K1

K2


154

54. UCP Outputs To 29 - 32 Volt DC LOADSThere are two output driver chips on the Unitary Control Processor (UCP), the U5 chip and the U6 chip, they are located in theupper left hand corner and the center of the printed circuit board respectively. These chips are used to energize andde-energize on board and off board DC loads.

The U5 chip energizes and de-energizes the following DC loads, and the outputs have the following load limitations:

Load Output Pin # Maximum Output Load Why Output Is Energized SYSTEM LED/LCD J7-7 27 mA (milliamps) To turn LED or LCD “ON”

SERVICE LED/LCD J7-4 27 mA (milliamps) To turn LED or LCD “ON”

COOL LED/LCD J7-5 27 mA (milliamps) To turn LED or LCD “ON”

HEAT LED/LCD J7-6 27 mA (milliamps) To turn LED or LCD “ON”

Outdoor Fan #2 (ODF2) J1-11 75 mA (milliamps) To de-energize ODF2 (turn “OFF”)

Power Slasher Relay J1-8 75 mA (milliamps) To de-energize relay if present

Defrost Relay (DFR) J1-13 75 mA (milliamps) To de-energize DFR (turn “OFF”)

The U6 chip energizes and de-energizes the following DC loads, and the outputs have the following load limitations:

Load Output Pin # Maximum Output Load Why Output Is EnergizedK1 On Board Relay NONE 75 mA (milliamps) To de-energize K1 (turn “OFF”)

K2 On Board Relay NONE 75 mA (milliamps) To de-energize K2 (turn “OFF”)





Exhaust Fan Contactor (XFC) J2-13 75 mA (milliamps) To de-energize XFC (turn “OFF”)

The U5 and U6 chip outputs for the relays are turned “ON” to de-energize the respective devices, this is done in a uniquemanner. This is accomplished by providing 29 Volts DC to the common side of the relay coil continuously, and when the U5 orU6 output is turned “ON”, 32 Volts DC is applied to the other side of the coil, the resultant potential difference at the coil isbasically zero. By turning the output “OFF”, and removing the 32 Volts DC, the potential difference at the coil is 29 Volts DC.See the illustration below.

Relay Coil De-energized Relay Coil Energized

32 VDC 29 VDC 0 VDC 29 VDC

Chip Output Turned “ON” Chip Output Turned “OFF”

Potential Difference Basically Zero Potential Difference 29 Volts DC


155

55. Software Change History

55.1. 3-25 ton UCP Identification And Software Change HistoryThe Unitary Control Processor (UCP) software capabilities can be easily identified, by noting the "X-CODE" (purchased partnumber) located on the P.C. board. The X-CODE will be located in one of two places, depending upon when the board wasmanufactured. The first production UCP boards had the X-CODE silk screened directly on the board (X13650384). The X-CODE was located in the upper right hand corner, next to the F1 fuse. All subsequent UCPs, beginning with X13650407, willhave the X-CODE printed on a sticker. The sticker will always be located in the same place, on top the K5 relay.

Version 1 X13650384 (BRD-0740)Description: First production UCP. Used in Voyager 8.5 through 25 Ton production only.Approximate production usage dates: 09/90 to 01/92

Version 2 X13650407 (BRD-0836) & (BRD-0838)Description: Interim production UCP - same capabilities as Version 1, added Demand Defrost to support ASHRAE efficiencyupgrade on Voyager 3 through 7.5 Ton products. Approximate production usage dates: 11/91 to 01/92

Version 3 X13650426 (BRD-0860)Description: Major production UCP - with the following changes:1. Added Demand Defrost.2. Modified Smart Recovery - used in Heat Pumps, provides smart staging of two auxiliary heat stages.3. Changed Supply Fan OFF Delay Time - changed from 90 to 60 seconds, in heat and cool, 3 through 7.5 Ton Heat Pumps.4. Added Selectable Dry Bulb Change Over For Economizers - values of 55, 60 or 65° F. can be selected on UEM.5. Added Stand Alone Unoccupied Mode - provides Set Up/Set Back and unoccupied functions, enabled by shorting LTB-11and LTB-12 (BAYCLCK001A / ASYSTAT668A).6. Added Sensor Only Economizer - using UEM (BAYDIAG001A), an ICS device can access supply air temperature on unitswithout the economizer accessory.7. Added Individual Fan Failure Detection - (AFF) Active Fan Failure Switch input (J5-3 & J5-4 on UEM), shuts downequipment, flashes SERVICE LED & alarms ICS device. Approximate production usage dates: 01/92 to 06/93

Version 4 X13650473 (BRD-0931)Description: Replacement / Production UCP - issued to resolve software defrost incompatibility between X13650426 andValera programmable ZSM when used in 3 through 7.5 Ton Heat Pumps.The following changes were incorporated into this version:1. Fixed defrost problem when X13650426 in 3 through 7.5 ton Heat Pumps was applied with a Valera programmable ZSM.2. Added Comm 4 Capabilities - capable of communicating at 9600 baud, with Comfort Manager II and Tracer Summit.3. Changed Control Loop - changed from 90 to 10 seconds.4. Added Decaying Anticipation - provides better droopless control.5. Changed Recovery From Set Back - eliminates over shoot.6. Added Scroll Compressor Protection - a compressor will not run for more than two minutes on a LPC trip. On a trip duringthe three minute minimum ON time, the compressor will turn OFF two minutes after the trip or at the end of the three minuteminimum ON time (whichever comes first).7. Added Logic For Compressor Lockout - a compressor will be locked out if the LPC opens, during the three minute minimumon time, on four consecutive compressor starts.8. Added Heat Pump LPC Trip Ignore Logic - an LPC trip is ignored if the outdoor temperature is below 0° F.9. Added Gas Heat Minimum ON Time - a four minute minimum ON time was added to the heat cycle to preventcondensation, the ON time includes igniter preheat and ignition trials.10. Added Economizer Preferred Cooling Logic - fully integrated economizer operation, compressors will not be turned on ifrecovering at a rate of 12° F. per hour.11. Changed Economizer Enthalpy Change Over Dead Band - changed from +/- 4 Btu/LB dry air to +/- 1/2 Btu/LB dry air.12. Fixed Jumping ZTEMP Analog Point - seen on ICS job sites.13. Changed Single Compressor Unit Data - will not show compressor 2 cycling input open on ICS job sites.14. Fixed Tracer Compressor Lock Outs - lock outs operate.15. Emergency Heat Status Masked Out - masked out in ICS data for non-Heat Pump units.Approximate production usage dates: 12/92 to 01/94 on Voyager 3 through 7.5 Ton Heat Pumps. Used in production forall other Voyager products 06/93 to 06/94.

Version 5 X13650508 (BRD-1007)


156

Description: Replacement / Production UCP - issued to resolve software defrost incompatibility between X13650473 and CTIwhen used in 3 through 7.5 Ton Heat Pumps. The following changes were incorporated into this version:1. Fixed defrost problem when X13650473 in 3 through 7.5 ton Heat Pumps was applied with a CTI.2. Added capability to defeat gas heat 4 minute minimum ON time. Systems with “NO” economizer - Pins J2-15 and J2-17must be shorted together at the UCP, with economizer installed - Pins J4-2 and J4-3 must be shorted together at the UEM.3. Fixed COMM4 Start Up Problem - changed address reading rate from 28 seconds to 3 seconds.4. Fixed “Test Mode” - X13650473 enforced the gas heat 4 minute minimum ON time in Test Mode, this was removed.5. Fixed Comfort Manager Problem - changed ECONOMIZE slave state to FAN ON when an economizer is not installed.6. Added Condenser Fan Windmilling Fix - when changing from one condenser to two condenser fan operation, all compressorand condenser fans are turned OFF for 7 seconds, providing compressor 3 minute minimum ON time has been met. At whichtime condenser fan 1 & 2, and compressor 1 are turned on simultaneously, compressor 2 if required is turned on 1 second later.7. Added 2 Minute ICS Start Up Delay - if TCI is installed, the unit will start with MODE = OFF and FAN MODE = AUTO,for 2 minutes. If the unit does not receive communications before this 2 minutes, it will start up stand alone, using local control.8. Eliminated compressor lockout function below 50°F when using a CTI.Approximate production usage dates: 01/94 to 12/94 on Voyager 3 through 7.5 Ton Heat Pumps. Used in production forall other Voyager products 06/94 to 06/95.

Version 6 X13650509 (MOD-0143)Description: Replacement / Production UCP - Scheduled hardware release, coincides with Voyager 27.5-50 ton release. Minorhardware changes were, so that all equipment (3-50 Tons) could utilize the same base board. A resistor and diode were added tothe U5 chip LED outputs, that protects the U5 if 24 VAC is applied to this 32 VDC circuit by chopping half of the sine wave.Approximate production usage dates: 01/95 to 12/95 on 3-25 Ton equipment.

Version 7 X13650564 (MOD-0305)Description: Scheduled release to support the implementation of the Texas Instruments Ignition Control (IGN) module in theVoyager product line. The following changes were incorporated into this version:1. Fixed a bug which prevented cooling from occurring, if the zone temp. is greater than 87° F., and it is “OK” to economize.2. Eliminated the gas heat 4 minute minimum ON time. Provides better control, eliminates overshoot due to over sizing.3. Changed economizer supply air low limit from 45° F. to 50° F., prevents cold air from dumping out of supply air diffusers.4. Changed filtering on supply air temperature channel, to make it faster, and to reduce the lag seen in the low limit function.5. Added compressor “lead/lag” capability. The function ships disabled. It is enabled by cutting the purple wire at UCP J1-7.6. Eliminated Power Slasher (2 speed supply fan) function, to free up resources needed to implement compressor lead/lag.7. Added 1200 baud communication capabilities, allowing the programmable and digital ZSMs to enable the “Supply AirTempering” function on a non-ICS installation.8. Fixed a bug which prevents lockout of compressor #2 if LPC2 opens during the 3 minute minimum ON time, on 4consecutive compressor starts.9. Added a 3 minute delay between compressor stages (CPR2 will not be turned “ON” until CPR1 has been “ON” 3 minutes).10. Changed supply fan start delay for gas heat operation from 45 seconds to 30 seconds (supports TI’s new IGN).11. Added incremental arbitration logic, incorporating a 5 minute delay when switching modes from heating to cooling (or viceversa). Prevents erratic temperature swings when equipment capacity is too great for application.Approximate production usage dates: 12/95 to present on 3-25 Ton equipment.

Version 8 X13650591 (MOD-0380)Description: Scheduled replacement part implementation expedited to address COMM4 communication problems.The following changes were incorporated into this version:1. Fixed a high temperature input nuisance problem on COMM4/Comfort Manager/wireless zone sensor applications.2. Fixed a communication loss problem when a wireless zone sensor is used with Comfort Manager.3. Verifies Tracer sends valid heating and cooling set points (greater than 50 °F.).4. Fixed a bug where the indoor fan turns off for 1 second when the outdoor fans are staging up, occurs only when fan mode isin AUTO and it is not suitable to economize.5. Fixed a bug where the UCP cycles Heat Pump Switch Over Valve(s) ON and OFF, when Tracer is in control, and notsending the UCP valid heating and cooling set points.6. Fixed condenser fan wind milling bug, where cycling dead band was 64.9 - 65.0 °F., instead of 60.0 - 65.0 °F., causingexcessive compressor cycling under these ambient conditions.Approximate production usage dates: 08/96 to present on dual compressor models, 11/96 to present on singlecompressor models. Current replacement part 03/96 to present on 3-25 Ton equipment.

Version 9 X13650617 (MOD-0432)


157

Description: Replacement / Production UCP - implementation expedited to address condenser fan software glitch on 12.5, 15,and 20 ton heat pumps with dual condenser fans.1. Fixed a bug where if the 12.5 - 20 ton heat pump “starts up” in the cooling mode, and the outdoor air temperature is between60.0 - 65.0 °F., no condenser fan motors are turned on. This results in the equipment locking out due to high discharge pressure.Approximate production usage dates 10/96 to present on dual condenser fan heat pumps, 01/97 to present on all othermodels. Current replacement part 10/96 to present on 3-25 Ton equipment.

55.2. 27.5-50 ton UCP Identification And Software Change HistoryVersion 1 X13650509-03 (MOD-0143)

Description: First production UCP. Used in Voyager 27.5-50 Ton production.Approximate production usage dates: 10/94 to 12/95

Version 2 X13650564-03 (MOD-0305)Description: Scheduled release to support the implementation of the Texas Instruments Ignition Control (IGN) module in theVoyager product line. The following changes were incorporated into this version:1. Fixed a bug which prevented cooling from occurring, if the zone temp. is greater than 87° F., and it is “OK” to economize.2. Eliminated the gas heat 4 minute minimum ON time. Provides better control, eliminates overshoot due to over sizing.3. Changed economizer supply air low limit from 45° F. to 50° F., prevents cold air from dumping out of supply air diffusers.4. Changed filtering on supply air temperature channel, to make it faster, and to reduce the lag seen in the low limit function.5. Added compressor “lead/lag” capability. The function ships disabled. It is enabled by cutting the purple wire at UCP J1-7.6. Eliminated Power Slasher (2 speed supply fan) function, to free up resources needed to implement compressor lead/lag.7. Added 1200 baud communication capabilities, allowing the programmable and digital ZSMs to enable the “Supply AirTempering” function on a non-ICS installation.8. Fixed a bug which prevents lockout of compressor #2 if LPC2 opens during the 3 minute minimum ON time, on 4consecutive compressor starts.9. Added a 3 minute delay between compressor stages (CPR2 will not be turned “ON” until CPR1 has been “ON” 3 minutes).10. Changed supply fan start delay for gas heat operation from 45 seconds to 30 seconds (supports TI’s new IGN).11. Added incremental arbitration logic, incorporating a 5 minute delay when switching modes from heating to cooling (or viceversa). Prevents erratic temperature swings when equipment capacity is too great for application.12. Revised so as to allow Tracer, when in control, to control the supply fan mode to either Auto or On, with theexception of when a VAV unit is in occupied mode.13. Fixed a bug which would not allow the supply fan to come on when the economizer is called to open and Traceris in control.Approximate production usage dates: 12/95 to 10/96.

Version 3 X13650591-03 (MOD-0405)Description: Replacement / Production UCP.1. Fixed the Exhaust Fan set point problem when a NSB is installed on a CV unit. The exhaust fan would not come on untilthe economizer damper was at 100%.2. Fixed the Supply Air Reset Set Point and Supply Air Reset Amount problem when ICS is installed and in control on aVAV unit. The problem is if either local SARSP or SARA fail on the VAV set point panel located in the control box, the unitwill not do reset even if ICS supplies the set points.3. Fixed a High Temp. Input nuisance problem on comm4/comfort manager/ wireless zone sensor application.4. Implemented comm4 service mode support to be compatible with Voyager 1 & 2.5. Added a diagnostic for failed supply air pressure sensor on VAV units. This diagnostic will flash cool and servicesimultaneously half a second on half a second off.6. Verified that tracer sends a valid heat and cool set point greater than 50°F.7. Fixed the problem with the supply fan turning off immediately on a VAV unit with gas heat when heat is on and the modeswitch is turned off. The supply fan should run 90 seconds after the heat turns off even is the mode switch is turned off.8. Added code to allow the ability to send an echelon zone temperature.9. Fixed problem with MWU starting the fan to soon if the unit has only been in unoccupied for less than 7 minutes.10. Removed 7FFF on VAV occupied sensor and set points in SCAN data when unit is unoccupied.11. Fixed the supply fan 30 second delay on for gas heat units during an off mode to unoccupied transition and a call for heat.12. Fixed counter for high duct pressure count out and clear the counter during and CV operation.13. Revised supply air pressure algorithm to reduce the IGV position by half when the pressure is greater than 1” w.c. abovethe supply air pressure set point.


158

14. Added a 5 minute waiting period when transitioning from any CV mode to a VAV occupied cooling mode.15. VAV unit with economizer installed problem only. Fixed the economizer from being locked out during cooling periods.The problem existed when the machine had gone into an unoccupied or NSB time period and then returned to occupied VAVcooling. When unoccupied the CV economizer algorithm locked out the economizer (does not allow to open above minimumposition) and then returned to the VAV occupied cooling period. The lock out is based on the zone temperature and the CVzone cooling set point, if the zone temp is not greater than the zone cooling set point – 1.5 degrees a flag is set to lockout theeconomizer. The VAV economizer algorithm did not clear this flag.Approximate production usage dates 10/96 to present all 27.5-50 ton models.

55.3. 3-50 ton CTI Identification And Software Change HistoryA change also occurred with the Voyager Low Voltage Terminal Board (LTB), which additionally drove some wiring changes.The hardware of the CTI remained the same, but the installation wiring diagram changed. If components installed do notoperate together, it will not damage the CTI or generic control, but a different wiring diagram may need to be used.

Accessory # Usage Dates Notes And Changes

BAYCTHI001A 06/90-03/92 Was not compatible with a Honeywell T7300 applied on a Heat Pump.BAYCTHI001B 04/92-05/93 A resistor change was made, making the CTI compatible with T7300 /

Heat Pump applications.BAYCTHI001C 06/93-Present Equipment LTB wiring changed, changing installers guide wiring.

Conventional Thermostat Interface (CTI) Application Matrix

Equipment 7th Digit 11th Digit Accessory Installers Guide Tonnage Unit Model Unit Model Model Number Required

3-7.5 C&D A BAYCTHI001A&B ACCSY-IN-60/18-HE60D72 3-7.5 C&D B BAYCTHI001C CTHI-IN-1 / 18-HE60D85 3-7.5 C&D A BAYCTHI001C ACCSY-IN-60/18-HE60D72 3-7.5 C&D B BAYCTHI001A&B CTHI-IN-1 / 18-HE60D85 8.5-25 B&C A&B BAYCTHI001A&B ACCSY-IN-60/18-HE60D72 8.5-25 B C BAYCTHI001C CTHI-IN-1 / 18-HE60D85 8.5-25 B&C A&B BAYCTHI001C ACCSY-IN-60/18-HE60D72 8.5-25 B C BAYCTHI001A&B CTHI-IN-1 / 18-HE60D85


159

C

Coil Temperature Sensor ................................................. 61Communication................................................................ 11Conventional Thermostat Interface........................ 8, 11, 16CSP............................................................................ 34, 55CTS.................................................................................. 61

D

Default ................................................................. 12, 34, 61DFM .......................................................................... 15, 62Diagnostics ........................................ 12, 61, 62, 67, 75, 78

E

Economizer...................... 13, 14, 43, 49, 50, 52, 53, 54, 60Economizer Set Point ...................................................... 53Electric Heat .............................................................. 12, 58Emergency Stop............................................................... 12ESP .................................................................................. 55

G

Gas Heat .................................................................... 56, 58

H

Heat Pump9, 10, 13, 18, 19, 20, 21, 24, 25, 26, 28, 29, 30,34, 59, 61, 62, 63

HSP............................................................................ 34, 55

L

Lead/Lag.......................................................................... 13

M

Minimum Position Pot ..................................................... 54

Mode ............................................12, 34, 47, 56, 58, 59, 61

O

OHS .....................................................................32, 50, 51Outdoor Humidity Sensor ....................................32, 50, 51

R

Reference Enthalpy ..........................................................51RHS............................................................................32, 51

S

SAS ..................................................................................49Smart Recovery..........................................................13, 63Space Temperature Averaging .........................................13Staging .................................................................12, 13, 47Supply Air Sensor ............................................................54

T

Test Mode ..................................................................67, 78

U

UCP7, 8, 13, 14, 15, 16, 17, 26, 27, 34, 44, 48, 49, 52, 54,56, 58, 59, 60, 61, 62, 63, 67, 75, 78

Unitary Control Processor......................................7, 14, 49

Z

Zone Sensor Module8, 9, 10, 11, 12, 13, 18, 19, 20, 21, 22,23, 24, 25, 26, 27, 28, 29, 30, 31, 33, 35, 37, 44, 47, 56,58, 59, 61, 62, 75, 76

Zone Temperature ................................................27, 34, 52ZSM8, 9, 10, 11, 12, 13, 18, 19, 20, 21, 22, 23, 24, 25, 28,

29, 30, 31, 33, 35, 37, 47, 56, 58, 61, 75, 76, 79


159

C

Coil Temperature Sensor ................................................. 61Communication................................................................ 11Conventional Thermostat Interface........................ 8, 11, 16CSP............................................................................ 34, 55CTS.................................................................................. 61

D

Default ................................................................. 12, 34, 61DFM .......................................................................... 15, 62Diagnostics ........................................ 12, 61, 62, 67, 75, 78

E

Economizer...................... 13, 14, 43, 49, 50, 52, 53, 54, 60Economizer Set Point ...................................................... 53Electric Heat .............................................................. 12, 58Emergency Stop............................................................... 12ESP .................................................................................. 55

G

Gas Heat .................................................................... 56, 58

H

Heat Pump9, 10, 13, 18, 19, 20, 21, 24, 25, 26, 28, 29, 30,34, 59, 61, 62, 63

HSP............................................................................ 34, 55

L

Lead/Lag.......................................................................... 13

M

Minimum Position Pot ..................................................... 54

Mode ............................................12, 34, 47, 56, 58, 59, 61

O

OHS .....................................................................32, 50, 51Outdoor Humidity Sensor ....................................32, 50, 51

R

Reference Enthalpy ..........................................................51RHS............................................................................32, 51

S

SAS ..................................................................................49Smart Recovery..........................................................13, 63Space Temperature Averaging .........................................13Staging .................................................................12, 13, 47Supply Air Sensor ............................................................54

T

Test Mode ..................................................................67, 78

U

UCP7, 8, 13, 14, 15, 16, 17, 26, 27, 34, 44, 48, 49, 52, 54,56, 58, 59, 60, 61, 62, 63, 67, 75, 78

Unitary Control Processor......................................7, 14, 49

Z

Zone Sensor Module8, 9, 10, 11, 12, 13, 18, 19, 20, 21, 22,23, 24, 25, 26, 27, 28, 29, 30, 31, 33, 35, 37, 44, 47, 56,58, 59, 61, 62, 75, 76

Zone Temperature ................................................27, 34, 52ZSM8, 9, 10, 11, 12, 13, 18, 19, 20, 21, 22, 23, 24, 25, 28,

29, 30, 31, 33, 35, 37, 47, 56, 58, 61, 75, 76, 79

Documents

Microcontrols 7DEOHRI&RQWHQWV - ComfortSite€¦ · 1.1.3. ZSM Current Zone Sensor Module Descriptions ... 28.1. Test 1: Verifying UCP Communication With UEM ... Microcontrols The